We've been using an AIT-2 drive for five years now and need to buy
more tapes. The question is which AIT version of tapes we should buy?

The Wikipedia says that AIT is both forward and backwards compatible,
but doesn't really specify what that means. Would we gain anything by
getting AIT-3, 4 or 5 tapes in terms of capacity, or should we stick
with AIT-2 tapes?

Or -- is it about time to get a new backup storage system altogether?

//rasmus