I have the 200 CD/DVD model, which I picked up from Goodwill. Built quality is fine, but I can see where the inside could break down pretty easily over time being a plastic carousel. It hasn't scratched any of my discs yet, but I've only played about 5 CDs in there thus far. As far as loading, it takes about 10 seconds for it to load up a disc, perhaps a bit longer depending on the carousel positions of the former and new disc. Sound seems to be just about as good as the high end CD players I have; it certainly doesn't sound terrible and sounds better than typical DVD players for sure.
Personally, I love them since they're CD jukeboxes. Watching the carousel going around is just so cool to me. As much as I love using it, I wouldn't have bought it if it hadn't showed up at Goodwill, because for what they're going for on EBay (~$100), that cost would have been too much for me to justify buying it as my computer is already my main source and holds many times more albums. As far as my usage of it is concerned, it's more of a cool novelty item than anything.
Probably the biggest complaint I have about mine is the size - it's roughly 19 inches deep, which means it won't fit in most standard audio component stands (which are about 15 inches deep).