I'm a service writer for a large independent BMW repair facility; I deal with aftermarket warranties on a daily basis.
CDS isn't the best I've ever dealt with, but I was actually a bit impressed this morning when I called in a client's claim on a Cooper. The hold time was long (~35 minutes before I got a rep on the phone), but he was extremely good. Very courteous, very efficient, and very pleasant to deal with. I wish I'd have have written down the rep's name; he truly does deserve some recognition.
Just now I got off the phone with CDS again after having to add something to the ticket that we could not replicate/diagnose before making the first call this morning. I wish I'd have had the first rep again, especially since it was almost 45 minutes on hold this go-round. I believe the second rep's name was Raul. By far the rudest warranty rep I've ever dealt with. Quite possibly the rudest person I've dealt with in a long time. The guy threatened to send an inspector out because he felt that I was trying to claim false items on the tab simply to make the shop a few extra bucks. He actually accused me of such over the phone. I was then told that if I attempted to file a supplimental claim in the future on any car, he'd deny it.
On a positive note, they did approve all repairs and didn't argue about part pricing like a lot of bad warranty companies will. If they get rid of individuals such as Raul, I wouldn't hesitate to rate them among the best I've ever dealt with. Unfortunately, you're only as good as your weakest link.