The number of times I can't find a star bright enough to guide on using 15s guide exposures, I'd hate to rely on finding one for AO use for every image. There's just too many objects I'd have to pass up on. At least with the PME I can get such objects any old time I want with 180s exposures and 300s if I am more particular about it. (0.84"/pixel, fl=2180mm)
The thought of always having the hassle of AO vs having a mount which "just works" doesn't draw comparison for me
