As it stands now, the drawbacks of some "unbalanced" weapons outweigh their benefits. Unbalanced means:
-The feinting window is smaller; not a huge drawback unless you are dueling (unbalanced weapons are usually too slow to effectively duel anyway, so not a big deal)
-You suffer a delay after blocking with an unbalanced weapon (a HUGE drawback, since your opponent can just keep swinging without fear of a counter-attack)
Some 2H weapons (like the Great Maul and Morningstar) have awesome bonuses to compensate for being unbalanced (high blunt/pierce damage, crushthrough on the maul), so these weapons are somewhat popular. However, other unbalanced weapons (especially Bardiches, Voulges, and Maces) are now practically extinct.
I say add the following mechanic to unbalanced weapons:
-After blocking a swing from an unbalanced weapon (with either weapon or shield), you have a chance to suffer the "stagger" effect, based on the weight ratio between the unbalanced weapon and the blocking weapon/shield
-This effect wouldn't last long enough to allow the unbalanced-wielder to get a "free hit" in, but it would prevent an immediate counter-attack and the subsequent "block lock" that unbalanced wielders currently face
With the current implementation, I can swing my huge, heavy Mighty Great Long Bardiche at a peasant wielding a sickle, he blocks once with his puny farm implement like he's brushing away a gnat (defying all three of Newton's Laws of Motion) and then is in my face hacking away, and I can't ever counter-attack unless I can pull off a chamber or make him glance. This is ridiculous.
Blocking huge, heavy weapons should take a toll on the blocker. As a bonus, we may start to see more variety among polearms instead of everyone and their mother wielding a Bec.