I finally upgraded to Firefox 1.5 yesterday. I had been holding out for an Ubuntu
No big deal. I can figure out how to upgrade by hand. Everything went well and now I have a shiny new Firefox on my box. Firefox 1.5 seems a little nicer but the differences to the user do seem pretty marginal. It is faster but that is about the only noticeable improvement. The configuration dialog is completely different but not really better or worse than the old one. However, multiple profile support is completely broken, as far as I can tell, which is very annoying because I used that feature quite heavily.
In a normal day I run three instances of Firefox, one for each profile. But with Firefox 1.5 apparently you cannot run multiple instances of Firefox at all. If you start Firefox with the default profile and then execute firefox -P webdev you get another window in the default profile, rather than a new instance of firefox running the web development profile. The profiles all work if they are the only firefox process running. For example, if there is no firefox process running I can execute firefox -P webdev and I get Firefox 1.5 with my web development profile.
So my upgrade was pretty much a wash. I can read my subscriptions without my eyes hurting but I have to install a bunch of extensions in my default profile and change the way I work. It is just annoying.