Yikes. This is such a hard decision! I modify most of Cathe's stuff down to lower impact, and am able to do so with most of the stuff in CTX. She has quite a few ricochets in there, but I think she actually teaches a lower impact move before going on to these (same applies to other very high impact moves). It is kind of difficult to reach the intensity that Cathe does, because I don't like to do so many power 7's and 15's, and modifying those down isn't as easy. As for space, I have to modify somewhat-there are several double grapevines and other such lengthy moves which I just change to single grapevines. I use an 8X10 greatmats floor, and wish it were bigger--but that's true for every video I own...
Because I like less impact and more complex (Christi), I don't reach for my CTX DVD's for cardio much. But I do love them for the weight work and abs. They are worth it for these alone.
I LOVE my PS and S&H DVD's. If you don't need new cardio, I would go for these. If you are looking for real strength gains, I would go for these (CTX is more endurance--very tough, but I'm seeing more muscle form PS and S&H) They are chaptered beautifully.
After writing that all out, I guess my vote would be for PS and S&H.
Now here come the CTX fans to steer you the other way! ;-)
Wendy