I just bought my first bent, a Bacchetta Giro. It just felt right, ergonomically. I know that inherently a larger wheel must be more efficient once rolling. I wanted to like the Strada better, but I did not. The bottom bracket was just too high for a beginner benter like myself. My question is, are there some solid studies on the relative effieciencies of the 20" vs. the 26" wheel? What did I give up?