Stability in cross wind is definately an issue with SOT Kayaks.
Some have rudders - these add to cross-wind stability to be sure. They get in the way and are a pain for Fishing Kayaks (we're constantly going below deck, routing the electronics, etc.) so ours don't have them. But they REALLY help when the wind or current is ripping.
The Manta is disco, and that's too bad. I paddled one last summer in Marina Del Rey at a demo, and then in SB later that week - it was really cool. Lots of room, but heavier than the SP TW. My wife had the SP and it helped because she could keep up, as the Manta paddles slower.
There is a guy blowing them out on eBay... in Texas. I saw one for like $400 the other day - with the convertable top! You know that's a complete steal on a Manta.
Hey Chepar - have some Island Snow for me, and stop by the Kalapawai store and get me another Tee...mine is shreadded.
I miss that place.
kk