I have just done some testing with some hardware I have lying around, it appears that my 1gb ddr3 500mhz graphics card was quicker with this version of mir when there wasn't much happening on the screen, how ever when the screen got busy I lagged. using my HD6950 card I noticed I didn't even lag whilst the screen was "busy". to me it would appear more than its my Internet Connection due to it being crap and slower than most peoples (10 meg download 1 meg upload). it would appear my connection isn't bringing the signal in as quick as others. my other graphics card couldn't handle the mass ammounts going on on screen where as my high end one can. I think this is mainly down to internet connection as well as pc you have to hand.
unfortunately this is the case with all online games.
we need people to post there net speed and if they feel they move quicker or slower than the majority on this game, as I can get fibre optic in y area so I will never know until I move.