Finished Insanity MAX 30 yesterday, found it technically more challenging than either the original Insanity or Focus, but I also think that the structure (30 min workouts with regular water breaks) makes it less challenging in a way - easier to adapt to and work with, but not as hard as Insanity.
Still, I enjoyed it. Would do again. On average my MAX OUT times increased from around the 8 min mark to 15-18mins per workout, partly as you just get used to the video and know what to expect, but partly because it obviously does improve your ability and endurance.
I found a few of the moves quite hard to master, would not be a bad idea to practice form before you went for it with MAX 30, though I have come to the conclusion that I prefer using dumbbells to the weight of my own body to add resistance, its easier to master imo.
Straight back on to Focus T25 today though, have to keep active and I enjoyed T25 a lot last time around. Goal is to double the weights by gamma this time around. Need new pants again though, another size dropped, and actually bought a coat from M&S in size 'small'. As much diet as it is exercise I feel, but its all great fun.