I honestly don't know if I could tell in a blind comparison between round and stock biopace.. but after that one thread I saw which suggested they might be less efficient, i'm always going to be thinking about it hahaha

I do kinda feel like I lose a tiny bit of power in certain parts of the stroke, but it could all be in my head. I have some Biopace HP rings which are more round which I plan on swapping onto my Univega, but I was wondering if I should do the "biopace rotation trick" at the same time