I have been on REM, cycled of course, since the beta version...it is the TRUTH!!! You definitely cannot go wrong with it. It starts working from the first dose...honest. The sleep is phenominal even if it is only like 4 hours; it enhances recovery and aids in lean mass retention during my cuts. For the sake of sounding like an infomercial I will stop but it really does kick a$$!!!
As far as is concerned during some down time on the REM, I used some samples of this. It also provided some d*%n good sleep but I only used it for almost a week so my experience is limited. However, its effects were good during my short trial.
I would venture to say that you cannot go wrong with either product but because I am a USP whore and I have been on REM 4eva, I definitely recommend it without hesitation.