OK, I know it is cheating, but I change the filter every other oil change. I change at 30-35 hours and on the times where I don't change the filter, I use a vacuum bottle and suck the oil out. It leaves about one-half cup more than pulling the plug, and since I change fairly often, I can't see that hurting anything. That change takes less than 15 minutes, and is a "clean" operation. No cowl to pull (a bigger deal with a three-blade prop) and no oil on the exhaust. I can't get a quick drain to clear the exhaust pipe by enough to get a hose on it, so I have to pull the plug.
Bob Kelly