That seems like a pretty loooooooooong game!
Scott Nicholson (of Boardgames with Scott fame) in his review said that it plays 90 minutes with his variant. Does the full game really take 3 hours? I find that usually games for my group take about twice the stated time...and there's no way they'd play a 6 hour game. No...way.
It takes about an hour per player for the game as published. However, there are some nice variants around that are easy to implement, and shorten the game a lot.