I'm with Runcrazy Jo - I like I-Max 3 better than I-max 2 precisely because it IS harder - I like to do the blast-only premix after a more up-tempo step warm-up every 2-3 weeks or so.
That said, however, OF COURSE GET I-MAX 2. Once you've gotten it, the Fit-TV Fillet will never do it for you. It comes on the same DVD as Cardio+Weights, as was mentioned in an earlier response, and you can customize both workouts a lot. PLUS, the Cardio+Weights has an ab/core routine that, while not long in duration, never ever fails to burn!
Never let it be said that we didn't help you spend more money than you'd planned.
A-Jock