Naish wave sail owners – RDM mast advice

Sorry, another mast compatibility question. Have searched the forum and can't quite zero in on this one. I have a mast decision to make for a 2011 Naish Session (4.2)

I'm 70kg, and will be using it for onshore wave/ bump jump type conditions on a 76 SB Evo. I'd like to get as much range out of the sail as possible.

On a '2 kids & mortgage' budget, so my options are:
Used Naish Firestick RDM 60 370
New Gaastra RDM 60 370 (these are both roughly the same price – cheap)

Or

Spend quite a bit more for a 75

First question – would there be a noticeable difference between the Naish Firestick and the Gaastra? I'd have a new mast warranty with the Gaastra.

Second question – at my weight and intended use, how much more performance can I expect from a 75% mast over the 60% in this length. I'd like to know if I'd really be missing something in terms of handling and wind range.

Thanks for reading!

Thanks Zachery
That's useful to know. I checked the Unifibre table and also the dk website so sounds like the stiffness / curve should in theory be close.

So the second question, performance wise. I have a 90% RDM 400 already which I use in my 5.0, and can definitely tell the weight difference and responsiveness over an older 30% mast.
But - when you get down to a 370 length, and are talking about a 60% vs 75% - I'm guessing there is bug_er all weight difference. So it comes down to performance. I realise this is very subjective and there are so many variables to consider, but can anyone comment from experience of sailing 60% vs 75% in this length and any noticeable performance gain?

I've got a couple of naish sails and they run best on naish mast. Naish 60s are good at the price point. 100% is always best but if cost is the concern then stick with the naish 60 it will be fine.

My naish sails always rig that little bit better with my firstick mast over my severne gorilla.

Best to stick with the same company.