1.6 of Mozilla seems very nice to me as well. I thought that all firebird - firefox was is a stripped down version of Mozilla with no mail news editor bundled in. It must be basically the same as the core browser in Mozilla because it handles things very much the same.
I just didn't like the way the default browser was set up. I always liked clicking on the left little tab button and having a new tab pop up. In firebird you would get a large menu instead. The download manager in Mozilla was better than Firebirds and to get firebird working better I had to install extra parts and peices. Doing new installs weekly or more often I didn't want all of the troubles. So far with Mozilla all I have to do are a few pluggin installs and the default browser settup works well for me.
I must say that the antialiased fonts really make quite a differnece in appearence though.
There are seldom technogical answeres for behavioral problems.