If you were waiting to try the restoration project until most of the bugs were fixed, then you'll be happy to learn that they have been:
Version 1.1 of the Fallout 2 Restoration Project is now ready. Hopefully most, if not all, of the issues found in 1.0 are fixed. Starting a new game is not required, but many of the fixes will not take effect unless you enter the area for the first time (New Reno and EPA are such examples) Thus if you haven't made it too far I highly suggest starting a new game. It's not required though and old saves will work just fine.