There were a few games that multiplayed between console and
PC... Like need for speed underground for the PS2.
But that really doesn't matter, the control is easy.
I suppose a good way to do a test is to get a very good xbox gamer and a very good
pc gamer together and have them play against eachother on the
PC version of halo. While the sample size is small (and therefore the results not definiative) it would be a good starting indicator).
Nice write up btw, I think this stuff needs to be spot-lighted some how if you are to continue doing it.