Has anyone tried KA Koncept and Race as well as Point 7 AC-K. My KA Koncept 8.3 (2008 I think) needs replacement and I want a bit more stable sail when it's overpowered with a good bottom end as well. So I'm thinking of a KA 8.7 Race, a 8.5 Koncept or try out the Point 7 AC-K 8.5. I have both a KA and Point 7 490 mast? it's for an RRD Xfire 122 and I'm 83kg. Any suggestions and comments are very welcome.
I used the KArace 8.7 2013 model on rs5 122 and it is not too big for the board. Wind around 13-18 knts, fin Sonntag 45, choppy conditions. I found the sail felt a bit heavy once getting overpowered, but probably I need to work on the tuning to get the best out of it. I heard that 2016 karace sails are a lot ligher to handle, but have no direct experience.
i also used that sail in lighter winds with bigger boards, all my sessions with the KARace 8.7 are here:
martignoni.id.au/sessions.php?sail=KA%20Race%208.7
Later years Koncepts in my opinion are much better and smoother, but the larger sizes are cut very flat, no bottom end power.
2014 and later Koncepts actually have significantly deeper profile down low than 2013. If you find them 'flat' something is wrong with your mast or the way you rig it. Having said that, I saw Boombuster's 2016 7m looked a bit flatter on his Loft RDM mast, but it was working extremely well for him like that. At high speeds flat water reaching in lighter winds, a flatter profile can be very fast on a larger sail!! 
If you want more top end stability in those larger sizes, the KA Race is the choice. The KA Koncept is a little lighter and slightly better marginal wind performance in the bottom end. Not much difference when in their sweet spots.
