I never sailed windsurf board on Sniardwy lake, but many years ago sailed small yacht on almost all Mazurian Lakes. Wind on Sniardwy is really convenient.
It's a fact that conditions on Zalew Zegrzynski are rather difficult. Thanks to this it is the best place for intensive training. I met there Steve Allen, Wojtek Brzozowski and other professional riders.
On other hand it is only spot close to me - 5 km, the next nearest - 150 km.
I'm considering about iSonic 144 (2010 - very good offer now), but rather inclining to freeride board like JP X-Cite Ride, Exocet Sting or Starboard Futura. I think freeride boards are more controlable on chop and small Baltic waves. But today I still can't decide
P.S. Woman with my extended family is living in Belgium, married with Belgian