Potter was always a solid bottom pairing guy here. He made some errors, but you expect that from your bottom pairing when they're outmatched against better opposition.
But he could get the puck out of trouble, usually took his man, played with a bit of physicality, and had a nice shot. Perfectly functional 6/7 guy, and I honestly think he could play in that role for most teams in the league. But Edmonton often used him to anchor the bottom pairing, and also doesn't hard match. I'm not sure he's suited to anchor any pairing in the NHL, and like most other bottom pairing d-men, he can't play against top opposition without being exposed.
He's a perfectly useful #7 guy on a cup contender, in my opinion. I'd rather him than Nick Schultz when the chips are down.