I have one and it's great. I have a similar issue where if I press in a horizontal plane I'm likely to experience shoulder pain. I don't know that it's impingement, but that's neither here nor there.
The big thing is that it help keep your elbows tucked and gets the pressure off of your shoulder. Get used to it at light weight. Sometimes I still don't get to do my full program, but it's definitely an improvement.
That's my experience with it. I should mention I bought the wild boar based on the weight I was working with.