I have used the Nautix ones for past 12 months,easy to adjust, nil corrosion if washed after sailing
Ive used GA adjustables,spring corrodes, harness goes to full length. 
Radz adjustables metal ring for boom attachment rusts thru. Both in about 1year. I sail n wash my gear in saltwater frequently.
NP adjustables easy to use.
Im looking at the cleat style by ION CHINOOK etc. Apparently super easy to adjust on the fly.
I have used a few different race style cleat adjustables. They all failed after 1-2 years, the webbing broke. Ions were the best to use and adjust on the fly, chinooks adjust easy also but flap about in chop and fall out of the hook quite easily. I am using Maksior now however the alloy cleat is bolted onto the webbing with a stainless bolt and nut and electrolysis occurs resulting in corrosion and failure.
Now I have a combination of all three brands working pretty well together
The ION Clamcleat ones are great, ION also have a new metal cleat one that is able to be removed and replaced with a new one when it corrodes.
I am totally old school in this respect. I mostly run fixed length lines but have attachments on the boom that are not too tight so I can move them on the go. I mainly use this to adjust for the centre of effort in the sail for upwind, downwind, changes in wind strength and after adjusting the outhaul etc. But I also use it to subtly adjust the effective line length when desired by moving the attachment points further apart or closer together. This only works though, because I keep them a minimum of about 9-10" (22-25cm) apart, far too wide according to all the new skool experts. 
I have the Neil Pryde ones and Gaastra, both are good. Easy to adjust, stay the same length and don't move on the boom. Recently bought a set of chinook adjustables for my new boom. I don't like them. They slip (increase in length as you sail).
Chinook have 3 types of adjustable lines so....
The "Inflight" are less easy to adjust but more rigid. I haven't had mine slip though? The "Race" lines are the best on the fly type - the 2017 ones used a hard plastic tube that did bounce around a bit in chop but the rope slid through super easy, the new ones use the heavier clear tube & don't bounce around as much so might be a good bet.
Sailquik, +1 until i find what adjustables i need. Ive got a fixed set that are too long n do the same. Have to run them wide to shorten them. Same kinda spacing as the 80s.Only drawback is it dulls the feel of the rig a bit.
for on the fly adjustment the Clamcleat style work well.
I have been using Tuna Fish lines and they are good but seem to chew the boom grip more than normal.
the Ion and Nautix look ideal.
Select to expand quotesailquik said..
I am totally old school in this respect. I mostly run fixed length lines but have attachments on the boom that are not too tight so I can move them on the go. I mainly use this to adjust for the centre of effort in the sail for upwind, downwind, changes in wind strength and after adjusting the outhaul etc. But I also use it to subtly adjust the effective line length when desired by moving the attachment points further apart or closer together. This only works though, because I keep them a minimum of about 9-10" (22-25cm) apart, far too wide according to all the new skool experts.
Daffy, maybe you need sails where the centre of effort doesn't move around. 
I have same problem with Severne adjustables slipping - clips were not moving freely (due to salt/corrosion?), so would not close up with pressure from webbing pulling them tight, have sprayed silicone, now move nicely, hoping that will fix things ...
Select to expand quotegorgesailor said..
Chinook have 3 types of adjustable lines so....
The "Inflight" are less easy to adjust but more rigid. I haven't had mine slip though? The "Race" lines are the best on the fly type - the 2017 ones used a hard plastic tube that did bounce around a bit in chop but the rope slid through super easy, the new ones use the heavier clear tube & don't bounce around as much so might be a good bet.
I have two set's of the race line's. One is the older one that does swing a bit free, and the other is the new one with the clear tube all the way that can be trimmed to desired length. This has made them better. I think it may have a bit better gauge rope too. I was looking at the Ion one's, but they didn't turn up.
I use the Neil Pryde race adjustable, work well on my three booms. They have lasted really well, I'm sure my spar set is a few years old.
Select to expand quoteAUS4 said..sailquik said..
I am totally old school in this respect. I mostly run fixed length lines but have attachments on the boom that are not too tight so I can move them on the go. I mainly use this to adjust for the centre of effort in the sail for upwind, downwind, changes in wind strength and after adjusting the outhaul etc. But I also use it to subtly adjust the effective line length when desired by moving the attachment points further apart or closer together. This only works though, because I keep them a minimum of about 9-10" (22-25cm) apart, far too wide according to all the new skool experts.
Daffy, maybe you need sails where the centre of effort doesn't move around.
Ha Ha!
I have sailed lots of other top brand race sails, in recent years Rick, including the brand you sail, and none of them are any different/better in that respect from my KA's.
I just like to have absolutely neutral feeling in my hands. I am a very sensitive guy.
Select to expand quoteolskool said..
Sailquik, +1 .....Only drawback is it dulls the feel of the rig a bit.
I might be old , but I am very newskool in that I am a very sensitive guy with very sensitive hands.
Select to expand quotePeter Hands said..
I have same problem with Severne adjustables slipping - clips were not moving freely (due to salt/corrosion?), so would not close up with pressure from webbing pulling them tight, have sprayed silicone, now move nicely, hoping that will fix things ...
Mine are new so the clips move fine, it's like the webbing is just to hard for the clip to bite into. It makes your heart jump when your flying along maxed out and your lines suddenly get 4inches longer
thanks for all the answers
I do prefer fixed lines too, but due to using my boom for slalom and foiling, I really need the lines shorter when foiling.
Doesn't seem to be a brand standing out from the crowd though....
I might check out the ION ones
Select to expand quoteseanhogan said..
thanks for all the answers
I do prefer fixed lines too, but due to using my boom for slalom and foiling, I really need the lines shorter when foiling.
Doesn't seem to be a brand standing out from the crowd though....
I might check out the ION ones
You can always fit two lengths of lines to each side, I've seen it done.
if you're not adjusting on the fly then any adjustable line ( that doesn't slip) will do the job,
Be aware of lines with toggles or handles at the end. A couple of friends have gotten those wedged into spreader bars before - not a fun thing under the sail.
Switching to a seat harness and that I raise the boom (since my foil board is a lot wider than the boards I'd normally use those sails on) about 8 cm does the trick for me.
Select to expand quotePaducah said..
Switching to a seat harness and that I raise the boom (since my foil board is a lot wider than the boards I'd normally use those sails on) about 8 cm does the trick for me.
Thanks, already doing that stil need a few cm less especially when powered up
Select to expand quoteseanhogan said..Paducah said..
Switching to a seat harness and that I raise the boom (since my foil board is a lot wider than the boards I'd normally use those sails on) about 8 cm does the trick for me.
Thanks, already doing that stil need a few cm less especially when powered up
My bad. This is the only other thing I can offer: keep the current lines and just increase your reach? (hope your search for the ideal lines bears fruit)
Select to expand quoteseanhogan said..
thanks for all the answers
I do prefer fixed lines too, but due to using my boom for slalom and foiling, I really need the lines shorter when foiling.
Doesn't seem to be a brand standing out from the crowd though....
I might check out the ION ones
Why don't you get another rig with shorter harness line for foiling? They make specific foiling sails now.
A lot of discussion over a little bit of rope and spaghetti.
Why don't you just man up and lose the lines altogether, problem solved. 
Select to expand quoteseanhogan said..
this should be in the foiling section
@jusavina : and double the booms ?
Off course
Select to expand quotesailquik said..
I am totally old school in this respect. I mostly run fixed length lines but have attachments on the boom that are not too tight so I can move them on the go. I mainly use this to adjust for the centre of effort in the sail for upwind, downwind, changes in wind strength and after adjusting the outhaul etc. But I also use it to subtly adjust the effective line length when desired by moving the attachment points further apart or closer together. This only works though, because I keep them a minimum of about 9-10" (22-25cm) apart, far too wide according to all the new skool experts.
I use adjustables but I also do that method of adjusting the width.. I've got the Nautix camcleat adjustables which I like as I can adjust them on the go if necessary ( lightwinds otherwise I stop.. ). I did cut some of the covertube off so I could adjust them a bit shorter if I need to.
Hi Guys,
Here is a link to possibly the best adjustable harness lines on the market: www.maksior.eu. They are great for Raceboard, Windsurfers, Kona, Bic Techno or RSX as they allow really easy adjust from strong wind (short lines) to light wind (long harness lines) while racing. Here is the page, the cost of DHL to send it from Europe is arround $90 but if your bulk order is more than $550 allows for free shipping.
The adventages:
1. easy to adjust while racing
2. dont damage the boom grip
3. 70% of Olympic Class RSX uses those lines. It takes 2 years for them to go through them.
Best Regards,
Max Wojcik
