You are probably a smaller environment, what LTO was designed for.  However,
there are many differences in LTO and Magstar.  Magstar recovery from a
damaged tape is much greater because of the way the data is recorded.  LTO
drives are about $10K each and Magstar are still about $45K list.  Even with
significant discounts Magstar is still going to be more expensive.  The
upgrades from B1A to E1A are going to probably cost as much as LTO drives
already cost.

The ultimate question is will LTO's reliability and drive mean time to
failure ever equal that of a Magstar.  That remains to be seen.  If your
tapes are not more than 5 years old, they need to figure into the cost
equation especially if you have a lot of them.

LTO is a good product for what it is designed to do.  Provide an open
replacement to DLT.  You will have to assess whether it is the right time to
make a change.

I would do a Total Cost of Ownership over the next 3 years for both
scenarios.  Consider fabric in the picture if you think you are going to do
that.  That upgrade is another $7K for Magstar per drive.  I would get
quotes from your vendors for all the pieces.  Yes, this is a lot of work,
but money talks when the costs are significantly different.