I was using Perpetuem for a while and it seemed to be fine, but when I used it on a moderately difficult hill climb I think it gave me a bit of an upset stomach. It might have been a combination of perpetuem with endurolyte capsusles, but I'm not too sure about that. I also noticed it had a slight fishy smell.

Right now I'm trying out Spiz (www.spiz.net) and I'm going to give Sustained Energy a try as well at some point. I'm still in the experimentation phase ...

If I recall correctly, Veronica prefers Sustained Energy. Mixed with Gatorade.