I thought about this for a while and yesterday I first tried one of the unofficial CM10.1 builds for the GT-I9100. It is nice and I really appreciate the work codeworkx did.
I can tell you that it has not reached the CM10 level, yet: the UI is laggy and in my tests the camera and gallery didn't work. I am actually downloading today's build since there is an interestingly long changelog.
Moreover a rumor says that tomorrow we will have the first official builds (yes, they aren't official yet, even if codeworkx developed them... I think they want a certain stability to call a ROM official). In about an hour I will give you another update and I will make some serious tests with the new build to give you the best bug list I can give you (maybe you'll see a video, who knows?). Stay tuned!