I think some that aren't familiar with a real good cassette deck are quite surprized when they hear one. It's a great format, "user friendly" and good sounding when the tape and deck are of high quality.

When I use a deck with no bias adjustment, I usually find one of two brands that work best. Teac and Maxell CrO2 or metal tapes are usually best. But when I have adjustable bias, I can usually make most any tape but the ultra cheap ones sound pretty good. Of course, Fe2O3 tapes always have a little more bass and less treble, but with the right bias setting, I can make them really sound pretty good, flat out to probably 16kHz. The metal tapes are easy to get dead flat out past 20kHz.