My CE just finsihed putting the latest microcode on the drives.  You would
not belive the difference this made!  My databse backup that had been taking
4 HOURS completed in 10 MINUTES right after the code was applied.
Perfomance improvement is an understatement!

I executed the command to write to tape again, and it completed in 8
seconds, a major improvement.  We also tried writng 16M to tape for a
comparison, and it completed in 13 seconds, so some of that time must be to
locate on the tape.

Thank so much for all of your help and suggestions!