What mast extensions do you use or recommend?
Euro-pin or US-cup?
Carbon or aluminium?
Brands?
45cm, Skinny, Euro-pin, Aluminium.
Sold by windsurfing sale under the Gun brand.
Heavier than other brands but cheap.
Haven't had it long enough to comment on durability
The NP MXT extension is pretty good. Had mine for about a year and a bit now no problems, works great. Good quality.http://www.neilpryde.com/matrix-2009/technology/matrix-system-2009-mxt-extension-base.html
If you're using an RDM, NP for sure. I've had them the last two seasons and the 2009 ones are great. Pull down by hand to maximum tension no problemo. Stands up to a decent beating if you're into big jumps too.
Chinook skinny aluminium with the cup (two pins on a spring clip).
I've had one pin break off once or twice, the unit still holds together and you find out when you de-rig. I like this sort of redundancy 
Not so sure about the Euro pin, I've seen a couple of these separate (once due to sand in the button mechanism, once due to the pin breaking). I'm always suspicious of a mechanism that you can't see. The chinook system is easy to see, it's simple and strong.
That said a friend's Chinook cup separated two weeks ago, but this was due to trying to mix and match two brands that were different sizes -- the cup was a very sloppy fit.
Easy answer, Aeron now do a Universal extension, You can use both Euro Pin and Classic Cup, you can get them in skinny or standard...
I've been using the Aeron carbon Skinny for a Year or so and had no problems...
yep - chinook ali - with chinook bogey uj -- 2 pin cups ---perfect/stongest combo
I've used both over the years and they all wear out after a couple of seasons
im currently using a carbon skinny extension extend out 25 cms with no problems
the euro pin im using did seperate for the first time last week not sure why
go carbon extension with a us cup as best combo it will wear out quicker
but shouldnt seperate
Don't be tight when buying extensions or bases, you really get what you pay for here. A mate had to swim a long way the other day due to buying a copy of a chinook deck plate, saved $20 but then had to swim 1km with his rig and nearly lost his board luckily it washed up on the beach.
Ive always had chinook extensions and have never had any problems except for an early batch of RDM's which bent when used with lots of extension. I also had one break a few months ago but it was over five years old and was broken by a very heavy wave!
Second generation techno limitz wave.. Simple, big rollers, made from some kind of scaffold pole, super solid...
I really like the look of the Streamlined skinny euro pin extensions. Dead simple elegant design. However I haven't used one and its pretty heavy.
You can't go past the MXT extension for large race sails in particular. I had to use a crank on my RSR 7.8 when set on the UXT base, on the MXT it can be downhauled easily by hand. The only thing to watch for is dragging the rope through the cleat, it is quite aggressive and can cause damage.
Chinook euro pin seems ok to me. The pin is one-piece, seemingly unbreakable, unlike the flimsy ones made by other brands. It's a good fit and I think it would take a miracle for it to detatch unexpectedly.
