My anecdote: I had been buying the CompUSA branded CDR blanks. After having gone through maybe 6 stacks of 50 without any problems, the 7th stack produced 5 coasters for the first 5 CD's. So I took it back to the store. Apparently customer service is instructed to argue vehemently with any customer. After waiting in line for 20 minutes and seeing several other customers getting pissed on, I was told that I had "no proof" that I had bought the CD's from CompUSA! They only said CompUSA on them! After 30 more minutes, and going to the CSR's supervisor (who told me it must be my burner), and then _his_ manager, I was told that "just this once" they would allow an exchange. The original CSR then very slowly and sarcastically counted off every CD on the spindle, pulling them off one at a time to make sure all 50 were there. Meanwhile, the customers behind me in line are of course getting pissed off at me and at the store. Never again.
One more thought on the Plextor vs. Sony debate. The $80 difference will also get you a brand-new hard drive, in the 20-30 GB range. I assume that the most common cause of buffer underrun would be because the hard drive heads are having to shuttle back & forth to meet the demands of different programs. Set the CD recorder and your new hard drive on their own IDE channel(s), and partition off 750 MB that is dedicated solely to recording CD's (so there's no problems with defragmentation). Enjoy the extra 29.25 GB's you bought with the money savings.
Btw, using a second hard drive to hold a dedicated partition for Windows' virtual memory is a good idea for similar reasons (significantly better performance on the 1st hard drive, lack of defragmentation, better utilization of multiple IDE channels).