The biggest issue with cassette tape was that they suffered from two issues, noise and 'Wow and Flutter'. Noise issues were resolved in some decks but even some expensive decks had unacceptable wow and flutter, which is the speed of the tape varying slightly as it spun. A good deck that controlled this plus had good noise control could make cassette sound very close to the quality of a good CD. Mix cassettes made on a good deck were very nice to listen to in the car...