Low Max is a good leg and cardio workout. I've had it for a long time, and it has "staying" power (I don't get tired of it). It's different from the Low Impact Series (some people have asked on this Forum whether Low Max is worth getting once they have the LIS, and I say emphatically, YES!).
The video clip gives you a good sense of space requirements. You do need to move around the step and to the sides. The furthest movement away from the step comes around 3 minutes into the clip. I work out on a 5' X 8' carpet and to avoid going off the carpet, I start my lateral movements off center (e.g., when I need to move to the right, I start from the left instead of the center). I hope that makes sense.