I played for the first time yesterday. Came up against 4 split screeners, easily finished off the 20 headshots I needed for the Weekly. I was surprised not many people were using the pistol, the rate of fire is great for quick headshots.
Overall though I found it boring. Like a really slow paced Call of Duty Hardcore match. I didn't find it particularly useful for assassinations either, Regicide is by far the best for that.