It has trimmed me up some, coming back after having a baby, and realizing I wasn't going to get to the gym on any regular basis, with two small kids! Gotten me some muscle tone and some compliments on my arms and legs. Also looking forward to the time when it just maintains me !

Lots more energy, better sleep, happier...the usual exercise perks!! The abs sections are great.
I have a touchy knee, so I modify too. I use my step platform only, for now, and I don't jump up off the step during the "power 15's", (that is, I don't "catch any air" but I do DO them) and I sometimes don't do ricochet's (too twisty), I'll just do the substitute she recommends, like repeaters instead. Also the plyo moves, I really watch it....I'll run in place, do kick's, or just do every other plyo. My knee can't take plyos, but it is improving.
My heart rate still gets up there, even with all of these mods. I really don't think it makes a big diff aerobically...at least not til I am an official aerobic goddess that needs that type of extra stimulation....
I am excited to have 5 30 minute aerobics sections to choose from, for when I go into my next rotation, which will be more weight oriented, and only about 3 days a week, 30 min per, of aerobics. I am an ectomorph, need to build more muscle, need to do less aerobics to avoid burning off the muscle I am trying to build, so that works for me.
Meaner Legs is a killer. It is an awesome butt workout. I feel it everywhere.
Jen