I have tried every companion except Currie and Hancock. And so far in my experience the women and X6 have been the best with a gun. I outfitted Piper with a modded out legendary 10mm and she is a bad ass with that thing. She is also deadly accurate with nades. Same with Cait, she made a comment when I got in PA once, "sure what am I suppose to wear". So I gave her a set of T60 and Ashmaker and watch her clean it up.

Preston can't hit the broadside of a barn with his laser musket, Deacon and MacCready seem to stay back and take pop shots and throw ill-advised nades. X6 is the only male companion so far that is proficient with a gun. Nick and his pea shooter are nearly worthless. Strong annoys the hell out me but he is a pretty good melee NPC. Even Danse hasn't been able to match the abilities of Cait and Piper in my experience.

I was wondering what is your opinion on the subject?