I was looking into it, and the answer seems to be fine if you (1) don't reuse hardware -- just buy exactly the components on tonymacx86; (2) don't install OS updates on release but wait until people have figured out how well they work and tweaked the hackintosh software; (3) are willing to suffer some pain around making imessage work.

edit: the key to a good experience seemed to be finding a working configuration then leaving it alone. If you want to update the OS regularly, you'll probably be unhappy.