If you were to buy all the right parts and do your research before starting... then yes, it can be just as stable as the "real" thing. BUT it should really only be a fun thing to do.

I don't really think people should plan out and build something just to be a "hackintosh", I think it should be something you already have laying around or have other uses for.

But that's just me, if I was going to be running OS X full time I would just get the real thing, even I had to get a used one.