I think this game sorely needs a SPRINT key (a la Wolfenstein).
When a grenade is tossed at you, it would be nice to be able to run your ass off.
And I think that while sprinting the gun shouldn't be usable (remove it from view as if it was holstered?)
It's so annoying being blown off by a grenade you saw in time but weren't able to escape because of the slow-paced running...