Anybody tried out the new Gu Roctane? I've just started using on my long runs, 16+ miles, and I think its has made a real difference. My legs seem to feel a lot stronger in the later miles but I'm not sure if this is the Roctane or the effect of training and me being excited about trying a new product. I'm trying it out under race conditions at the OKC Marathon this weekend so hopefully I'll have a better idea after that. Thanks for the thoughts and input.