Critical hits are fun...
But it's a shame they're not more tactical. ie: When you've earned critical hits (ie: your next shot(s) are going to be critical) it's a shame you don't know this. So you can save that shot or know it's a critical one.
Or, a count down on your screen so you know when your critical hits are going to go active. So you can try and be in the right place at the right time...
Plain random = not very skillful...
Crits arent fun

Crits have to be random otherwise it makes unbalanced teams even more unbalanced. If you make the people who survive and kill more have crits then youre just helping them kill even more.
Crits should just be left out altogether and that way everyone has equal chances of killing someone providing they dont suck

Hopefully none of the other Heavy weapons will have crit related stuff

My Demo with more crits is bound to be fun >.> lol