Hi Wouter,
We live in two different worlds/populations when it comes to catamaran sailing. I saw two T4.9s for the first time in my life two weeks ago. This F16 class stuff must be big in Europe but where I sail, it is so small I can't see it. I understand the T4.9 is a one or two person boat. That's fine, but again where I sail, I don't see them. No US builder builds a one or two person boat, boardless beach cat, that I know of. Hopefully both classes will prosper.
Good Sailing,
Bill