Happily owned this sim for a few months now, definitely the best gMotor2 based sim around. Not really tried multiplayer too much, but I know of leagues that use the sim so I would imagine that the servers aren't confined to Reiza servers. In terms of their old F1 content built into the game, there are skin packs to give you the 'feel' of racing against real life competition but then there are also mods like the F1 1992 mod which give you a proper field of cars, although F1 1992 is purely a very good LE.
1999 German F3
1989 Italian Superturismo