Several things strike me having read this post.
If you have done Tabatacize this week already, and then did Imax 3, you may have felt more pressure afterwards in the joints and back because both of these involve seriously high impact, and maybe you just maxed out on impact for the week?
Secondly, I wonder if the difference between floor impact moves and step impact moves is at work here? I think we all have a preference and find one or the other of the two easier. Maybe, you find floor-based HiiT/tabata/plyo work easier on your body? I know that I find the step versions of these easier to perform, so, this would have an effect upon my perception of both dread before, say, Crossfire, and how I felt in my body after it. Give me To The Max any day.
Of the three Imaxes, number 3 does have the most impact of all. Cathe really turned it up a notch; I remember not liking this at the time. However, having now seen the tabata stuff, the HiiT stuff, Intensity, Drillmax, Crossfire, etc, I'm not convinced that Imax 3 has any more impact than these others.
You inspired me to view the Imax 3 clip here again, since I have not done it for about 8 years, and I have to say I liked what I saw. The music is rocking, and what's present in Imax 2 and 3 is the cardio sections in between the blasts which are fab. Some of her best choreo, certainly better than some of the low impact choreo I have seen lately which just doesn't do much for me. So, I think I will always prefer Imaxes over Tabata. Besides blasts in tabata, what else is there? Sure, it is terribly efficient. But is it really fun?
It may, in the end, all boil down to: what's your cup of tea? What makes you feel beter and what do you most enjoy doing? You don't need to do any workout that makes the build up of dread before it tur the whole thing into a nightmare until it is finally done. What's the point? If you dread Imax 3 and have no other feelings for it, retire it or sell it! It's like books and buses: there'll be another workout along in a minute! So many workouts, so little time.....
Clare