netcode wise, it goes...
ki >>>>>> sf4 > mvc3 >>>>>> mk
mk was just really bad. it had the worst input delay out of them by a long shot. ki uses a ggpo type tech so there is no input delay at all and it is incredible how good it it, and this is after capcom flat out lied and said that ggpo was not possible in sf4 because ggpo type technology doesn't support 3d models, only 2d sprites. well f u capcom, you were caught red handed cause ki did it no problems, even with a spectator mode.
sf4 has the little input delay as well but nowhere near as prevelant as in mk.