back in my 4 tracking days I used the TDK SM and SA. They are the best tape probably. But then My four track just basically became a 2 track recorder for rehersals and stuff, just record it, then throw it in the car tape deck. Sounds Wierd, but I swear the Maxells sounded way better on normal speed than the TDK's, like it took to the noise reduction a little better. If your using high speed and bouncing stuff, re-recording stuff, the Maxells will crap out on you sooner that the TDKs. Just a thought.