I remember when I was experimenting with the new concept of big, high pitched props in pattern, and wanted to get with the the times. I switched to a YS long stroke with whatever prop Hanno was using, I think it was something along the lines of 12x11. I immediately noticed a severe loss in vertical performance where the aircraft would noticeably slow down in an upline. It was disappointing to me at the time, and If I had stuck around in pattern, I would have gone back to the fast Rev-Ups.

Any thoughts as to why my experience stunk?

My thought is that the higher the pitch, the less efficient it is under a direct load, similar to the gearing in a car.