Thanks for the kind words. Unfortunately, the only Futura I've tried is the 101, so I can only guess how the 122 and 133 would work. I've used the 101 with superfreak 7.0 and speed demon 7.5 - both worked well.
Still, I think it will come down to how much you value that super light wind performance relative the "fooling around" performance. But if you don't intend to do jumping tricks it sounds like the 133 would give you the most added benefit relative what you already have. After all, you can always take out the Aero (in wave mode) if you feel like you want to have a tricking day. And the 133 would offer an even more stable platform for some lightwind sail spinning and stuff. And most of all, my guess is that even a superlight 10m2 freak (or 9.0) would be better handled by the bigger 133l board. Not that it could not be made to work on the 122, but t will surely be a more natural and comfortable fit on the 133. I also think that the K96 would start working well long before the F133 tops out.
But maybe someone else have tried both the 122 and 133?