I personally find it a tad underwhelming that the 200+ promised new features turn out to be just around 10 new features, with each minor tweak apparently counting as one whole feature of its own. I would expect safari to count as 1 improvement all on its own, not 7-8.
I guess that's why it is so cheap. You really get what you pay for.
That said, here are my observations.
1) Safari is no replacement for chrome. It still doesn't feel as smooth, and I find that when I pinch to zoom, the text simply expands beyond the entire screen, unlike chrome, where the page readjusts itself to fit the current borders. Maybe when ios6 brings icloud tabs to my ipad...
2) Dictation is still as unreliable as ever, and apparently, I spit a lot when I talk.
3) Notification center is great, and I may just go back to using mac mail because of it.
4) My imac seems to take longer to shut down. Not really an issue though.
5) Never really used notes or reminder before ML, now seriously giving them a serious relook.
6) Imessage working fine.
7) Haven't bothered with game center, VIP mail or airplay yet (what's the point of streaming from a desktop?).
Anything else I overlooked?