This was most certainly not similar to my first reaction. For the first two week it was always "WHY Da F DEOS THIS NOT WORK LIKE WINDOWS/UBUNTU!!!!????". There was an adjustment period, but now I think OS X ML is my favorite OS, certainly the it's the one I spend the most time on, but it won't replace Ubuntu for running a development server anytime soon. It actually has replaced windows for most of my gaming, except for CS:go, but only because it's horrid with a track pad, and if I'm going to hook up a mouse I might as well just boot my windows box and sit at a desk, and break open some scotch, and get angry.
There are still things that are better elsewhere. Finder is no replacement for nautilus, and I still miss what can be done with Compiz, and Spotlight is no match for gnome.do, or even Ubuntu's default search not even close. I even think that the windows start menu search is a bit better at this point.
Over all the best thing about switching to OS X is that the number annoyances is quite low compared to the competition, things like not having to open xorg.conf or mess with buggy beta video drivers, or getting nagged by Windows update once a week. That makes it worth it.