Over the years, I've had 5 TDSxxx series scopes, and I still have a few. The common issues are:

NuColor CRT displays going bad. Bad capacitors. Dallas NVRAM units battery running out of juice

Fried electronics are pretty rare.

We had some "ghosting" on the displays on a few now that you mentioned it, but they were still 100% usable. I guess my expectations were lower since I never had to foot the bill for the lot of em (which at 20k/unit I guess I'd be upset about when one was faulty)