this is my take. I feel the high wheels put more leverage on the axle/wheel it self and could cause the wheel to break over time. I just picked up a Toro recycler with the normal size back wheels. I think there's something else to it but I can't put my finger on it.

 

a high wheel mower is more manuverable. I know some will argue but the science will tell you the larger wheel will give you better leverage for pivoting the mower . Now my suggestion would be get a good commercial mower. you will notice that these mowrs seem to make a comprmise with a larger rear wheel but not the massive rear wheels of the cheap mowers. . also the commercial mower will have a better engine heavier deck and the wheels will be metal with ball bearings in them. As far as High whell commercial mowers you will only find a couple and these are built for less manicured sitiuations where you need the ability to move the mower deck around with ease.

 

I like 10" (maybe 12") rear wheels on a mower (like Snapper uses). They roll easier than 8", but don't have the problems of the really "high-wheel" mowers (the wheels tend to wobble as they wear, and you have to press down harder on the handle to raise the front wheels to turn--not a big problem when the bagger is full). Also, you can get high quality, ball bearing, steel 10" wheels at the hardware store for cheap to replace the worn out ones.