Slings are like holsters........you are going to end up with a bunch of them before you find one that you like.
The only sling I run on an AR anymore is an Urban E.R.T. It's the most comfortable I've found, plus I really like supporting Indiana business when I can. Mine's the E-RUSH model so it converts from single to 2-point, and is setup for QD mounts.
I've seen lots of people sharing good experiences with them.
I made my own two-to-one-point sling from paracord,2 HK hooks,and a 1" ring from the chain section at Rural King.
Be prepared for fatigue,blisters,and the use of swear words that never existed until you uttered them aloud in frustration.
Best to get a 100' length of cord(you probably won't use it all,but I've never heard anyone say " Damn,I've got too much paracord"),which can be had for ~$7,the ring is <$1,and the hooks can be pulled from just about anywhere.How's that for budget friendly?