I try to get used to any changes that software developers make to their software. I assume that there's a reason they made the changes. That's why I'm always defending Facebook when they change something (except their most reason chat system, but that's another story). I think that most things just take some getting used to. We're used to doing something one way, and when it changes, even if it really is a better way to do it, it's difficult to adapt at first. I understand this and try to work through it to realize the benefits of the change instead of longing for it to go back to the way it was (or complaining about it on the software's support forms).
One thing I just haven't been able to get used to is the new location of the refresh button on Firefox. They moved it to the right side of the URL entry, just to the right of the bookmark button. In older versions of Firefox, (3 and below I believe) the refresh button is next to the back and forward buttons. In its new location, it has also been made smaller, so it's even a bit harder to click (and you have to watch out for the bookmark button as well.
I've tried to adjust. It just doesn't seem natural for me over there. The solution is an easy fix anyway. Right click anywhere on one of the toolbars up top (though not on a tab), and you should see the Customize... option. This gives you a popout with extra buttons you can add to toolbars. IMO most of these extra buttons are pretty worthless and I'm glad they're not displayed by default. You can ignore this window completely. When you're in this mode Firefox lets you drag and drop components already on the toolbars. So grab the refresh button and move it over to the left (where it belongs!). Hit Done on the popout and voila. A better working Firefox!