Nope not true, people are already saying that the bugs they had on beta 3 are still there and not fixed. They said this rc only fixed background things.
I haven't installed it, so I don't know how it actually runs, but a couple people in this thread alone mentioned it was running pretty well, and that's with less than 30 posts (including repeats from people). Much higher percentage of people posting positive things about updates than normal. Just try to have a little optimism once in a while.