Hmm... Transgaming would have the old binaries... pity that it's impossible then.
I believe the performance comparison would be "interesting". Some of the games will be performing as good or better on Linux. Some of them will be slightly weaker, performance-wise. This isn't to do with Linux being weaker or Cedega being way better than ports (which it's not...)- it has to do with the skills of the porting team doing the work. Not everything is done efficiently when someone does the porting work (All I need do is point to the Shogo:MAD and SiN ports to make THAT point...).