On my Alliance I have tried both a 16x12 and a 17x10. I would use the 16x12 over the 17x10 any day. The extra speed it gives the plane means it locks in better and in fact the vertical performance seems better with it too (which is counter intuitive to my mind but still).

Scale it down a bit for a 90 size plane but the principles are the same. With the coarser pitch props the power "flows" better. Don't confuse constant speed with slow speed!