It feels like upgraded Burst Rifle + Sharpshooter is extremely powerful in the hands of a skilled player, but you still need to devote 4-5 points on a perk to make that build feasible. The TacShot only takes 3 points and is superior in close quarters to anything other than skill+headshots -- even unupgraded it's a beast.
This is a bit of a late reply but I've been terribly busy as of late. Sorry!
The Burst Rifle is nice when paired with Sharpshooter but it does just fine without it. I'd rather use the points on other stuff. At any rate, it's one less point than the Tactical Shotgun. At close range, the Tactical Shotgun faces some stiff competition against the Shorty and nailboards.
The Shorty costs two less points, has a huge spread, and it is difficult to gun down a Shorty user that bobs and weaves between shots. It is also costs way less to upgrade, especially if you forego the second upgrade which I feel is nice but unnecessary. As someone who's been on both sides of a lvl 2 Tactical Shotgun vs nailboard, both people go down. Perhaps someone else can offer their own anecdotes on this match-up, but upgraded melee probably wins if the Tactical Shotgun is lvl 0 or 1 due to the slower fire rate. In other words, the Tactical Shotgun gets trumped by something that is available to everyone regardless of loadout, for free no less!
These two things prevent the Tactical Shotgun from being the king of close quarters, if you ask me.
Just started playing the MP of this game and man is it overrated. [...]
Some of the DLC stuff is very good. But the non-DLC stuff is just as good if not better. Would I be happier if there was less paid DLC? Absolutely, but calling it pay to win is a stretch.
If you don't like that you can be seen through walls, consider using Covert Training 2; it prevents the enemy from detecting you with listen mode, provided you're crouching.
The slow character movement goes with the slower pace of the game. Flanking can be a very powerful tactic and it would be even stronger if you could get into position quicker.
If people are able to run away after you "pump almost a full clip into someone", I have to question how many of your shots are actually hitting your target. What weapons are you using? My first guess is that you use the Full Auto Rifle, in which case I would advise you to branch out and try something else. It doesn't hurt to wait a little before pulling the trigger if it
ensures that you won't miss. Too many times have I watched a beginner get the drop on a (stationary) enemy only for them to blow the opportunity by missing shot after shot.
Mid/long range kills take a bit of practice, that's all. You might find it easier with large firearms as they are more zoomed in than small firearms.