I would suppose, buying access to the manual upgrade guides would work fine as well. Personally i seldom use the "Upgrade package", even though i have customers who pays for getting them. Its often not feasible in a "enterprise environment" where everything is under sourcecontrol, every developer has a local copy of an installation and it progressively moves from integration to staging to production.
An automatic upgrade package is a noble though and might work for simple sites, but more often than not, i need to get my hands dirty and look in the guide to see what was changed.
An automatic upgrade package is a noble though and might work for simple sites, but more often than not, i need to get my hands dirty and look in the guide to see what was changed.