Petry is WAY bigger. Every time I see him I am amazed at how he seems to get better as he gets older, sort of like Markov. Definitely underrated. Having said that, Spurgeon is also a terrific player, and a personal favorite. Tiny, but superb defensively. Better, IMO, than Petry. Petry probably has the edge on him offensively, but Spurgeon is no slouch either. Spurge has an uncanny ability to raise his game in big moments, and make clutch plays at both ends of the rink.
I pick Spurgeon for my team, but no disrespect to Petry. Spurgeon is a couple of years younger. They both have similar career stats, but petry had a slow start in EDM. IMO, he has become a new player in MTL once he got his confidence back.