Well, I bought a Yamaha CRW2100S a few months ago, half the price of the Plextor 12/10/32S my mate bought around the same time, hooked it up to my Adaptec 2940 (no letters) while he connected to a Tekram 315U, and I haven't made any coasters yet, while he's made a few...
We weren't burning the same stuff, but I'd say the Yamaha worked well, quickly and moderately quietly (near silent burning/rewriting, playing much quieter than any IDE 40x CD or DVD drive I ever used). No problems with 80min CDs. I got the Yamaha rather than the Plextor for two reasons: (i) it's priced competitively close to the IDE writers; (ii) another mate already had one, and found it trouble-free. I've no doubt whatsoever that the Plextors are extremely good too though.