It's awesome, but it's still not nearly as frictionless as Chrome. My understanding of Chromes upgrader - as a user who only occasionally uses the browser since firefox is still my main - is that the browser auto-upgrades the first time you load it after the new version comes out. Now, I thought this was how the new Firefox worked, but since I did it manually today even after rebooting once for a plugin issue (Netflix doesn't fullscreen properly after you load it a few times - apparently it's an issue with the firefox plug-in container and/or silverlight), now I'm not so sure.
Either way, Chrome installs cleanly without the user even having to know it happened. Firefox, OTOH, causes the UAC in Win7 to halt everything for the upgrade. It's not as transparent as maybe it could be.
Firefox does update automatically. By default it checks for updates every 8 hours, downloads the update in the background, and installs it the next time you start Firefox. If you haven't restarted Firefox for 24 hours after an update is downloaded, it'll prompt you to restart. If any of your add-ons will be disabled by the update, Firefox will list those add-ons and ask whether to upgrade or not.
We're working on refining all of this; here are some of the things that may change in the default update behavior in future versions: https://wiki.mozilla.org/Silent_Update
Thanks for the clarification. I did think the Firefox update was automatic, but I think I confused myself by doing it manually today.
My main point was really meant to be the UAC, since it was a bit jarring to see today (First upgrade on Win7; just bought this computer a month ago). I'm glad to see that this is being looked into.
On the bright side, I had absolutely no issues with add-on compatibility this time around. In the old days, I would wait a while - sometimes literally months - before upgrading, because of issues with add-ons I considered "important". I actually ended up backing up my profile before any upgrades, and often had to roll back the version. I didn't even think of that today, I just clicked apply and everything worked. It's a serious improvement.
It's not quite as efficient as the "Courgette" algorithm used by Chrome, but it's much smaller than downloading a full installer. Hopefully we can use Courgette if the patent issues* are resolved.
