We are having great success with the os/400 client and are planning to
migrate all as400 server to tsm for backups...
We are getting approx. 8 MB/s  (you have to make sure that the Ethernet card
and the switch port is set at auto-detect or else transfer speeds are
terrible)

Robert Burton 
Enterprise Storage Network Analyst 
Royal Bank of Canada 
315 Front St West 
Toronto, On, M5V 3A4 
* 416-348-3849 
* Robert.Burton AT rbc DOT com <mailto:Robert.Burton AT rbc DOT com>