i like both sets of skins, but the vBulletin does appeal to me more, plus it reminds me of the old CadTutor.net so i stick with it. if it wasn't an option it wouldn't bother me either way.
i LOVE the quick reply, and other new features that vBulletin has to offer, and i think the switch was a successful one for all. also, i absolutely love the RSS feeds, i have learned so much from those, and what's good about them - they come to you, you don't have to search the info out. just taking a brief look at everyone that comes in, really keeps my brain fresh on old and new AutoCAD hints and tips.
so far so good for me, i love this being my second home while i have downtime at work. lol