I have done both. Right now I have to say that into week to they are comparible. This is my first week in using the EVO stack so I dont want to give you a false impression. NHA stack is great btw. As it stands you cant go wrong with either stack as long as your diet and workout are in check. The amount of gains really depends on you and your bodymakeup.
That being said....unless you are 21+ (I believe for both stacks) dont use it.