I have been using the leaked firmware since the day one. Changes are actually quite small compared to the hype bubble that has been growing for months now. Overclocking (running 1.1GHz) has improved the overal usability more than the unofficial 1.1.2. I'm happy with this RC cause it seems to be quite stable with my usage.

Could Nokia have released this RC at extras-devel repo for those who are eager to test?