The main reason for our switch?
We never, ever, ever got through a backup without having to call in IBM
and replace a drive. We figured replacing all cards, cables, drives and
library ought to remove the culprit. And, other than replacing the logic
unit on the new library after a full system save took HOURS too long and
the GUI web interface was strange as hell, we had no further issues. (This
was on a less critical lpar.)
Of course the pi$$ing contest about whether or not the new library is
under maintenance was unpleasant. Apparently contracting IBM for the
install and testing of the new library, having copies of the emails
requesting maintenance, having dealt with crappy backups with the previous
hardware, etc, was all meaningless.