NR2003 wipes the floor in every aspect of physics. It's far more sophisticated, though obviously doesn't have the open flexibility. There are a couple of good mods for it too - ones which aren't primarily oval-based, like the excellent (though flawed in some aspects) GTP mod.
I did state rF was very good... just not in comparison to some alternatives if you're looking at the simulation aspects of it. It's hardly bad... just not aimed at quite the same people. If you want a recent F1 mod then it and GP4 are currently the only choices, and will probably remain so until Codemasters give up exclusive rights.