Patrik, I know they make both the Cadet and Futura in Fastroller air floor versions... I hadn't seen the Classic with an air floor.
Anyway the Cadet is the lightweight tender/sports tender model, the Classic is a heavier traditional design and the Futura is more of a sports boat.
In truth (compared to a true RIB) they are all going to offer similar performance.
The 3.4 Cadet Fastroller is about the lightest for its length they've ever made if that aspect is important to you.