In my experience nothing I've tried so far beats good old ephedrine. Craze, done maybe 10 tubs, tons of different DMAA products etc, but ephedrine is just better all around.
Problem is, there's only this 30mg ephedrine where I'm at, sold at way too high a price. It was ok when I could by 1000 count tubs of the 30mg ones for about 100 bucks out of the UK. I think they said they came out of Pakistan and sold for 10 bucks there?
Dymetadrine-25 was the shit, fond memories. First ephedrine I did 20 years ago.

I'm sure I'll get ahold of some Frenzy to see what it's like, but I would never recommend anyone else to try it. You'll be doing some research chemical with unknown effects and health risks.