I have tried the 26A through D. I didnt like the C or D at all, way too much load. The 26B is a smidge better for imac, but not as good for 3D and does not spool up as fast as the A. The 26A performs awesome at 3D, but for IMAC type flying I found it just ok. For your yak (I had same setup, 80cs and can) I prefer the A for everything. The B might be better for something lighter, but most of our 33%s are realistically 22-24lbs. My friend has been running the 26A on his yak for sometime now, and everyone with 80cc engines has been trying to get it from him.