Johnny,
We are very happy with TSM V6.2.2.0.

We upgraded from v5.5 to v 6.2.2.0 in December. It has been at least as stable 
and trouble-free as v5. No major problems, and no regrets. The run time of 
expiration on v5 nearly sank our ship. That went from a day and a half in v5 to 
an hour and a half on v6.2.2.  Other processes seem to run faster also, but I 
can't give you before and after data.

We boot our server from SAN, and did an image backup of the boot disk and an 
offsite database backup before the upgrade so we had a sure back-out. The 
database was about 200 GB at the time of the upgrade, and its conversion 
run-time was about 20 hours.   

Best wishes, 
Keith Arbogast
Indiana University