I'm with DS, alternating unit movement was the biggest improvement from SM2 to NetEpic.
We find 4-6K all play about the same amount of time.  Our 6K games look like a 4K game with more or bigger Titans/Gargants so in fact, 6K battles probably end quicker as there is sooo much more carnage.  The race also makes a huge difference..... Tyranid games take a looong time, and Squats can slow things down too.
We also a) have the board ready b) draw a quick map and let the other person setup while drawing placements (dont peek) c) dont allow passing, d) roll all attack dice at once and work out any targets afterwards (the different dice colour is a great idea!) which all help get a speedy game.  Some nights we chinwag too much though.....

ÂÂ
