Jimmie...
As an "opt out" adoptee, we just kind of jumped in blind. I looked at our Medicare rolls, figured we would take a significant hit if they all went away and were not replaced, and decided to do it anyway for all of the reasons you know but I was finding no longer tolerable. Our billings actually increased slightly the year following the decision, much to my surprise. I would never suggest our experience was typical, but others in this area who have opted out have not seemed to regret their decision either. We see Medicare under private contract, and as primary care, our charges tend to be pretty low in the scheme of things. We happily discount anyone for whom it would be an issue.
Now, remember, I live in a semi-rural area, there is a relative scarcity of physicians, and no contracts or managed care to deal with. There are certainly physicians on this board who practice in areas with mostly medicare and lots of competition, where medicare pays as well or better than most. As they say, "Results may vary...."