Just wanted to pass along a great experience with doing a TSM Upgrade!

ENV
RS/6000 H80 (4x8)
AIX 4.3.3
TSM 4.1.6 
TSM DB 100GB

Just by chance we read the readme for 5.1.7.  It stated 
Customers migrating from a prior release of Tivoli Storage Manager MUST
 1. First download and install 5.1.7.0 (Not 5.1.0.0 or 5.1.5.0)
 2. Then install license enablement and license certificates from your product 
CD.

So we took this route and the whole process too 4hrs instead of 8-10 from a 
similar env we upgraded from 4.1.6 to 5.1.5

Big time saver!