>Has anybody flown with donuts in the mains and then switched to the
air/oil
shocks?  How much difference is there in the ride?  Anything else I should
consider before deciding whether to switch?<

The difference is considerable,  landings will be smoother and they are
easier on the structural components of the gear too. I highly recommend
them. It is an easy mod but swing the gear prior to flight checking for
allignment, interference, and door closure clearances.

James B. Frantz
Proprietary Software Systems, Inc. www.angle-of-attack.com
LFrantz@compuserve.com
(952) 474-4154