Whichever one you will stick to consistently. It's a personal preference and I enjoyed RWH more but it is very intense with lots of cardio. Currently I'm doing ICE/ RWH and really liking that.
Jamie
In my opinion, if you want to burn calories while having fun - Xtrain is the better choice. This series has great music and varied intensity levels compared to RWH.
If you want to lose weight faster and prefer shorter, killer workouts and high impact does not bother you - go for RWH.
I personally do not have knee problems, but still prefer Xtrain.
I wish you success
Thanks for the opinions. I just finished with ICE and that is why I am trying to figure out what next. I haven't used either set yet and I just am having such a hard time trying to decide.