I've been running it for about 4 hours now without any problems. Haven't really noticed anything different.
As far as the download not working it doesn't look like that is the only one not available. I attempted to download Alltel 4.5.0.127 and got the same message.
with the sprint 4.5.131 with my apps i only had about 15k now with this update and same apps i ave almost 18k on the memory so that is a definite upside other than that haven't seen any other changes
didnt work. an update window comes up that says 4.5.0 core applications and i click update now, then it says no software update is required. i might redownload and run it again.