Well, I'm enjoying Firefox 4 so far, I've adapted fine, but there were somethings I just couldn't live with and I had to change.
I honestly feel like they are not targeting me anymore - Firefox will soon be a browser for "someone else", and I'll have to go elsewhere to get what I want. And I find many of their implementations to be terrible.
I thought the added customizability would make such things meaningless, but it really doesn't - hell, look at the status bar problem. The issue was never that they got rid of the status bar, for me anyways. Its that the replacement (the pop up thing) was TERRIBLE. It was constantly moving around, it was inconsistent, it offered less information than the thing it replaced, and it just didn't look very good. It also had a tendency to conceal the information I wanted to see (a flaw of popups in general, though not nearly as bad as firebugs quick info popup, though that at least manages to be more useful).
Luckily, the statusbar4ever plugin not only fixed the bar, but made it
better. It actually made it feel like I was using a browser that was an improvement (however slight) over the previous one. I really just don't understand how any of the changes they've actually made are supposed to be improvements, even just the changes in defaults - it feels like they are just attempting to copy other browsers with no aim or direction or cohesive vision of their own. Why move the reload/back button a screen away from the other page control tools? Why put the tabs further away from the location where your mouse is most likely to be? I mean, ultimately its not meaningful where they are located, as long as people are used to them - but why change it? What's the rationale?
Also I didn't actually get to try out the new menu button thing because I can't figure out how to turn it on.