I have the Scorcher set and enjoy it. For the most part, low impact but very intense/effective. Time flies by. Believe it or not, this is one workout where I don't mind burpees and sprawls. The background exercisers move at their own pace/level, and there is someone doing modifications w/a dumbbell instead of the KB. Be warned, Dasha talks non-stop. There are two timers on the screen, one counting down the entire workout and one for each interval. She interspaces 1 minute rests between 4-5 sets of work, and you will appreciate them. Highly recommend.
I liked Scorcher and 7-Day Lean so much that I bought her second release (11 DVD KB KB set) from Mary a few days ago. Looking forward to receiving it.