Saw a few pros running the game on 4:3, which we all know doesn't really affect player models but only stretches UI unless you do some Nvidia shenanigans on your monitor. I decided to try going from 1920 x 1080 to 1024 x 768 to see if it helped at all, and damn if it doesn't for me. Game runs a bit more consistently frames wise, and the crosshair being stretched horizontally actually helps me when it comes to aiming.
Keep in mind I'm not using black bars, but rather stretching the UI in 4:3 on my 16:9 screen. Might give black bars a shot, but so far this feels great!