If you are beginner in cardio, so you have problem with following complicated steps, if you have sensitive legs/back, so you cannot jump, if you have small place at home to exercise, AND if you have good sense of humour - I would recommend the Walk Away the Pounds tapes.
I do not know any other tape with real ( I mean everyday and not pro) people. I know many people feel motivated by watching wonderful people with perfect bodies exercising in wonderful mansions, or before wonderful landscapes. When I watch the otherwise nice Gilad tapes for example , I always wondering why the hell would anybody exercise in 120F, 10+UV in bikini in full make-up on the beach?
Leslie Sansone can be annoying, but if you have good sense of humour, you can have fun:-)
The other thing: this tape is not intimidating, exactly because of the mistakes. You feel so proud to be better even than Leslie:-)
For me the most important thing: this is the first tape my husband ever done. He is a very proud computer nerd, to lure he to do any exercise video is very hard. On the other hand during our last cruise trip he enjoyed a real life group cardio - full of amateurs. That is why I decided to buy the WAP videos: to have a fun exercise with my husband. (We run together, but that is so serious.)
About the impact of it. If you do it with full energy, it is as effective as an easy jog - without the pounding effect on your knees/back.
As I mentioned different people have different expectations, so I know this is not for everybody....