The d3 build I use in pvp.
I have decided to go with CHC and EDR instead of skill haste as I think the build still can crit hard and kill players. If you opt for skill haste, the shield can be back in about 20 seconds (around 30 at the moment), but still is too long to survive. If my shield is down and I am on my on, it's either try to run or back to the check point for me. 30% EDR on top of 600k toughness and 2.3 mil shield, give a much needed tankiness and survivability against nades (players spam them all the time against d3 as you really immobile), stickies (that are becoming more frequent) and of course pesky preds.
The two weapons are obvious. The first house with vicious/deadly to increase the CHC/CHD. When I am getting to low health, I try to run, and change the gun to unforgiving for increased damage in the last segment of health. The side arm is not important, the only thing is predatory to finish downed player for the health regen (I still need to get used to doing this :D).
Skills. It doesn't matter what shield is deployed as you always have the master shield. The second skill is optional. I prefer booster shot that works great after using a medkit at low health to increase the damage resilience.
Talents. The obvious ones are combat medic (d3 is for group play imo, and combat medic is absolutely vital), critical save (it works amazing when you proc it and then use booster shot) and adrenaline (to get rid of bleed). I usually run precision to increase the damage and reach max chc, it happens a lot as it's easier to headshot when using d3. Alternatively, on the move is a life saviour (it procs against players/npcs/skills deployed), if it gets tough, just focus on the nearest skill deployed to proc it and then use a medkit (to get on the move and critical save).
All in all is a great build to run in the dz, especially for someone with a potato aim like me. However, situational awareness and the ability to time the medkits right is vital. I don't think there's a build that can win 1v1 if two players have same skill level. Even, when surrounded, 1v2 or 1v3 I can still get at least one of the opponents.