I'm just wondering, I just put it on one of the comps this evening, and so far, so good. It seems to run a little bit smoother than Firefox, and I haven't had any mysterious closures so far. I may have gone a bit backwards from what I should have, first I removed all the mozilla items, then after I installed deerpark I copied the plugins over and reinstalled the mozilla-mplayer, it works, as well as the other plugins, just had to copy them over from the firefox plugin directory. I don't see much difference from firefox in terms of the layout, other than the prefs, which are tabbed on top instead of icons on the side. Overall seems the same though, just a little smoother and quicker.
<<edit>> correction, I reinstalled mozilla-mplayer, then copied the plugins, didn't want to confuse anybody