I know precisely what you are talking about, the pills I used to get back in the early 90's would tear your face off and had you rushing so hard you would be bent over with your hands on your hips as the euphoria freight train knocked you out of your Adidas shell toes. I've never found a pill or MDMA that has come close to recreating the effects of those early pills, I am also pretty confident no amount of caffeine, speed etc could create those effects either, there was definitely something different in them or the MDMA was different from what is produced today.