I got mine in November 2006 and already in December at the WC in Hurghada, Bogdan had brought a new version (slightly shorter blade and full corners). He said that he experimented with the glidefin all the time, and true enough, at Nordic Deep in August last year, I saw yet another version with the dealer there, but I can't tell you how it was different. Being a girl, I only remember that it had a different colour (blue, not pink) ;-) but from now on I will pay more attention to the different layering, position of foot pockets, shoulder reinforcement etc that this thread is bringing up. Interesting!
Interesting Evita; Your observations concerning your couch were both technically astute and detailed. Perhaps if you consider your monofin a type of sofa...