I have had a Strida 5.0 for three months but have no experience with previous models. I understand that when Strida was sold to Ming Cycles they bought the rights to do whatever they wanted to in future improvements. I'm not certain, but I understand the 3.2 and 3.3 are pretty much the same except for the introduction of metal wheels and ergonomic grips in the latter. The 5.0 freewheel is at the rear hub instead of at the crank, as in the 3.2 and 3.3, which I understand makes it more efficient when coasting. I further understand that the plastic bottom bracket housing of the 3.2/3.3 was prone to squeaking under hard riding, which is not a problem with the 5.0's metal housing.

I really like the the 5.0 for my short commutes and recreational rides.