I've had several decks with user bias fine adjustment on them. Still have a Technics dual-well that sounds pretty good (needs some new belts and rollers, though). The Tascam outperforms any of the others I've had, probably because the basic quality of the parts and the construction is better then the others I've had. A high quality unit without bias fine tuning might outperform a lesser deck that has bias tuning. However, a high quality deck with bias fine tuning would be like icing on the cake... I used to have a Pioneer CT-f900
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This was my favorite stereo cassette deck. I think it's the coolest looking component I've ever had. Mine finally died (record stopped working and most of the rubber needed replacing). Someday I may just get another one just for the cool looks. The three head design sounded good, too. I think it had user adjustable bias fine tuning.
I like TDK's top chrome (type II) tape when I can find it (getting scarce around here). Maxell's top chrome is next on my list. These sound great on the Tascams. Sony's CD-IT tapes are ok, but not quite as perfect sounding. I haven't seen Denon tapes around here for a while. I used to use them in my pre-Tascam days and liked them.
Dave