I felt that the best bike there after riding them all was defiantly the 280 gasser.  Felt good in every way. 
But i still felt that the Beta back end is the best going, but the bike does still feel quite big.  One big shock to me was the 4 stroke Montesa.  I thought that it would be quite a nice bike to ride, but i didnt like it and couldnt get on with it at all. 
Crosswaite can still ride a bit.  Impressive.