I usually do 85-90% water changes on all my tanks....once or twice a week, more often for juvenile fish that must be fed heavily. Eventually I'll get a drip system up on some of these tanks.
I don't see any benefit to doing small water changes instead, never have. As long as your tapwater remains fairly consistent from day to day it's not going to stress them, unless you're waiting a long time and letting your water parameters get completely out of whack before doing a very large change. As far as stress from the water levels dropping, if you do it often fish quickly get used to it, and many enjoy it and play in the new water coming from the hose. It's when you do large changes erratically that they're not expecting it and get stressed.
+1
Go S. Vettel #1 rb8