With all these complaints, it almost sounds as if 10.5.0 shouldn't have been released yet...
No, the problem is that some people here are just cronic complainers, some just want some features that were removed, other have done something weird to their systems and have blue screens and instability because of that.
I updated (yes updated) 2 laptops and 1 iMac with no issues and no hangs. All 3 run fine, only complain is using TM with a disk being shared is not working correctly, but there is an easy work around .... physically move the disk and plug it into the machine that needs to be backup until Apple fixes the issue.
No big deal, all .0 releases have bugs.