I run the 11.5x4 APC on a MVVS 40 with MVVS mini tune pipe set-up. It runs great in my area. I also this prop on my Webra 50 when I fly at higher altitudes. Normally the 11.5x4 APC is not enough prop for my Webra 50 with a Mac header and tuned pipe, though its a good prop.
If you are running a strong 40 or a 46, then the 11.5x4 APC is a great prop.
Kevin