I have an Epson R300. I love it. Have probably printed well over 500 CD's/DVD's on it in the 2 years I have had it. It can be a bit frustrating printing large batches (largest single batch so far was 100), but once you get into a rhythm, it isn't too bad. Reasonably economical on the ink also.
Except I use the R200. It is true that a large run of DVD's could be trouble some. My largest run has been 20.
But as I think about it, each printer only costs $100 or so. Buy five of them, and print five at a time, see the off the top of my head logic here. Anyway, it's about the best $100 I've spent out of all my equipment.
But on top of that it makes incredible photographs, so I've also started using it to print my DVD cases.