I'll be honest, I am happy with the current melee system. I was horrible with the MM one, and getting a new one would render me useless for a week.
Now I would really like some patchwork regarding ping. Melee is way too ping-dependent, and there have been many occasions in which my character launches his stab like 3 seconds after I released the left mouse button, or not never launching the stab at all.
Granted, I have an average ping of 300 in euro servers (Thank you shitty Argentinian internet), but still, it is an issue to be taken into consideration.