I have been taking c4 extreme for a few months and it isn't working as well as it once did. I am going to take a few months off from taking it. Is there some other good PWO supplement that I can take while not taking the c4? Something that doesn't cause a crash a few hours later? I was thinking of trying muscle pharm assault or Jack3d. Would either be good or is it too similar to the c4? Any recommendations would be appreciated.