The 3590's are the better drives...
(how many LTO drives do you see in MVS environments ?)
and especially if you have the E drives !
We are still running on 5 year old B1A's
(have about 40 or 50 of them around...)
the tsm environments take in a total of 2 TB nightly (on average)
In 5 years (best I can remember) there have been 10, maybe 15 tapes go bad
where I couldn't (easily) get the data off them (includes being eaten by the
drive).
On all of those (except one) the data naturally expired without being
requested.
On that one exception, a .dbf file was required, they retrieved it from an
earlier version and used redo logs to bring it back to the state they
needed...
So in short... In 5 years, all the clients here have experienced ZERO data
loss with the 3590's !

just my personal experiences...

Dwight