I am about to get  a 3575 to replace our 3570 tape library.  I don't want to
have to migrate all of the data to new tapes though.

The way I see it you should just be able to checkout of the 3570 and into
the 3575.  Or is this like the 3490 to 3590 that fails because it cannot
find a 3490 drive to mount to?

Has anyone done this?

Gary