Agreed. Since I use my Plextor Premium for CD burning most of the time, I don't burn data CDs faster than 32x (I burn audio discs slower), because at higher speeds (e.g. 52x), PowerRec reduces the speed at the end of the disc most of the time anyway. Besides, 52x is only 20-30 secs faster than 32x in my Premium, and the quality is usually worse. With most CD media available today, burning slower doesn't improve quality either, so 32x is the sweet spot for this drive.
I used to buy a lot of Mitsubishi CD media as well, and especially the old Verbatim discs (8x max.) with the dark blue Azo dye were just awesome. The newer Super Azo discs burn very well, but not as good as the Taiyo Yuden discs, at least with my drives that is.
A very good alternative to Taiyo Yuden and Mitsubishi is Sony media btw. (for Europeans at least), see this thread for scans. This media is rather cheap, and widely availabe here in Germany.