I've used the Tactical Mask a few times. This thing is pretty good. Shock charges have no effect on you, flash and concussions don't seem to do anything. It's a pretty good perk for a rusher that like to get behind enemy lines, or someone that likes to gaurd an objective that gets a lot of nades tossed at it.
Engineer is what I generally run. This thing is outstanding. Strap on 2 EMP or Black Hats and you are golden. It's nice being able to see all the Betties and Claymores around the map, but Engineer also allows you to run through them. When a guy is gaurding his back with a claymore, you can destroy it or hack it, sure, but now he knows you are there. Just rhino charge through his equiptment and put 3 in the back of his head before he knows you are there. With Engineer, you can also "reroll" your/teammates care packages. This is pretty good for those of us to still run care package. You have a chance to change that UAV into an Escort Drone.
I use Dexterity and/or Tactical Mask.
Dexterity is so useful its ridiculous that it is the first perk you get in that slot. And as you say TM is great, can save you from a lot of deaths.
I have tried engineer out a little, bouncing betties are making me want to throw my controller through my tv atm so i may start to use it more.
Apparently if you have a really good headset Awareness will allow you to actually hear enemy player footsteps. They probably should buff this so that it works no matter what sound output your using. The fact it is unlocked so late, i would expect it to be very good but i havent run with that much either.
I've seen lots of compalints about awareness. Honestly, I wouldn't even see it as being over powered if they made enemy footsteps sound different than your own teams.
I've never used Dexterity past lv 14. It looks like it's a great perk if you like to run around knifing people like a ninja.
dexterity just allows you to get the first shot off sometimes, if i run into someone who isnt using it and im gonna be aiming quicker so hit them quicker
I love rerolling my teammates care packages without their permission. I usually give them something better, but I laugh when they get screwed.
On my capping classes (for Dom, or for planting in Demo), I run tactical mask. Makes it much easier to get past shock charges on the way to the objective & avoid being stun-killed once I'm there.
On my anti-turret class I run Engineer so I can see exactly where my target is.
On my rushing classes I run both Extreme Conditioning and Dexterity. Combined with Lightweight this makes flanking & getting into spawns a breeze, and saves my butt when I round a corner & run into an enemy who didn't expect me to be there so quickly.
At some point I'm going to try out the awareness perk + messing with the audio settings to see if it actually helps me hear footsteps, but I haven't yet.