Are you deciding between an AR pistol (M400 PSB) and a mid-length carbine (M4V5)?

DD makes great stuff, I have a DD upper on a PSA lower. It's my favorite AR.

I've really never taken to AR pistols--I don't see the need/use other than having fun at the range. I have heard of people using the PSB as more of a stock, but that is illegal and I would never break the law.