We have one netstor server (3466, H50 RS/6K) that supports over 1500
desktops and servers - around 300GB a day in incrementals over 4 100Mbps
ethernet cards all on the same subnet to large diskpools (several trays of
SSA) and then into a 3494 tape library dedicated to this TSM server.
The DB is 75GB and at 88% capacity.

Yes, there are performance issues (sometimes very severe), but all the
issues deal with the TSM DB/log performance. Don't get me on that
soap-box...