2hers, especially greatswords and bastardsword are excellent dueling and skirmishing weapons. Winning a 1v3 is much easier with them than with any other weapon class.
What makes 2hers very strong especially on eu1 is that there is no teamplay, so a 2h hero wont have to face big groups but can backstab and get many easy kills, while in strat he cant flank without getting shot or bumped, and in close combat you will get the shit piked out of you.
But once you get into a proper, coordinated battle they lose much of their advantage. If there would be only strat i would immediatly take 1her or polearm over my great sword, if you work together in large groups the are much better than 2hers, its easier to survive in formation fight and you are more useful to your team using 1h or pole.