I finally got around to testing the Firefox 3.5 betas since beta 4. It's only been 8 days and I'm now using my fourth version.
I have to say that I'm startled at how much better Firefox is. But like I said before, I'm not surprised since Firefox has legendarily tangled code. Every version untangles a little bit more, making things faster and faster.
This is the thing I love so much about open source. As long as the project stops making stupid feature diversions and forks, constant effort always yields software that is increasingly better.
Mind you, it's really rare for a project to either not stop mid-stride and veer off in some strange direction, or not stop at the 80% complete mark and rot while the author gets on with life. But for the projects that have enough authors, or who have a small dedicated team .. well the results are spectacular.
Also, my neighbourhood's net connection got fiddled with, so unfortunately I can't tell if speed differences are from Firefox or a repaired/upgraded infrastructure. =/ I highly suspect it's Firefox because I have some locally-served stuff which seems faster.