Has anyone compared the recent pro models 8ft or 8.5/8.6ft for stability and paddling in these two brands? Do the Starboard boards have a touch more nose volume? How do they compare with rocker?

JP 8-6 pro v Starby 8-5 pro . The Starby is slightly wider , centre is further forward but it's thinner and 4 litres less . Rockers look pretty similar , maybe a touch more nose rocker on the Starby. Stability wise they should be fairly similar. Float wise if you are at the high end of the 80's or cracking the 90's the JP will be the more stable. Sub 85kg guys I don't think you would notice any difference between the two.

Piros,
I have an Straboard Pro8.5 and I,m 92kg and its really hard work for me in anything of glassy conditions.
Is the better stability of the JP something significant (and worth to trade the board), or more a subtle?

I ride the JP 8-6 pro and I'm generally 90 to 92 kegs , I'm fine on it surf it in anything. As I said above if you are around my fighting weight the JP will carry you better than the Starby. I don't think you will find it heaps more stable but it will be better. Hard to call to say sell one to buy the other.

I,m gonna try to organise a demo.

Cheers Piros