I'd like to hear your experiences with this (if you don't mind sharing). It's something I've been thinking of. Did you follow a guide like TonyMacx86? I figured if I went with recommended parts, then OS X wouldn't be a problem to run smoothly.
I used a recommended build from Tonyx86, and really installation was fairly smooth. After the proper multibeast kexts and a little tweaking with the network settings to get the App Store to recognize the computer as a real mac, I was more or less in business.
It was quite stable overall, but there were a couple things keeping it from being a 100% working install:
USB 3.0 would not work correctly for the life of me. The drivers included with Multibeast are experimental, and I didn't have luck with them. Now that OSX will be natively supporting USB 3.0, though, you may have better luck.
Sleep simply would not work correctly. If I slept the computer, all the USB devices would eject themselves and not reconnect on wake. Solution: just don't sleep...
OS X did not like my RAM running at 1600mhz, and the motherboard would often do a double reset thing that cleared settings and bumped it back down to 1333 (triple checked my DSDT stuff, all the OSX side stuff, no change). Windows didn't mind.
Most importantly for me, my USB audio interface did not like the hackintosh. It needed to be plugged in after boot or else no audio would be sent to it, sometimes spat out corrupted audio, etc. I tried different audio driver options in multibeast, eventually just opting to not install anything past vanilla in order to get a stable experience, but it never quite worked as well as it does on an authentic Mac. It was strange.
---
Ports not working, coupled with not being able to sleep the computer and a bad time with a very important peripheral left a somewhat sour taste in my mouth. I also know that Mountain Lion is coming out soon, and while the update process is much easier than it used to be, I would still be waiting and crossing my fingers when the time came to finally test the waters.
All that being said, I really did have fun with the build, and it was very cool to see OS X on a custom built rig. If you like to tinker and get a kick out of finding solutions to problems, then you will probably fare better than I. In the end, though, I run OS X because it just "works," and is a transparent experience for me as a creative professional. Compared to windows, OS X just fades to the background and lets me do my work.
---
The best way I can describe a hackintosh is a less-transparent OS X, where you find yourself wondering if you're going to kernel panic (I only had one, but that was enough), or if you could tweak something to make this part of the OS run better, or if you should chance that OS update you saw in software update today. It's only a few kbs, but it could screw up your whole installation. Better re-clone your boot drive before you try it...
They work, and in my experience they actually work well (the one kernel panic was an SNES emulator that could very well have been shoddily coded), but... something feels off. Maybe I'm just too picky; your mileage may vary.