Melee is working quite fine. It is very difficult to hit, but on the other extreme you have games where you just press a button and your character will align, bring up a third arm and deliver an unblockable attack that kills instantly, even while you are shooting them.
A fully charged bayonet is fantastic, though most my melee kills have been frantic rifle butting against opponents as shocked and unable to return fire as I am (ie out of ammo).
What I need to test and confirm is at what point a melee attack is delievered. Is it the moment you release the mouse button, or is it at the appropriate moment in the attack animation? Is it an extremely short range shooting attack or is the blunt/sharp end of the attack active for a few milliseconds and able to touch the enemy at any time for it's duration? This makes a huge difference in how to aim the attack.