His potential isn't as far from DeKeyser's as people think. I have watched both extensively over the past few years
DeKeyser's potential=Rob Scuderi
MacWilliam's potential=Matt Greene
Both are defensive defenseman with limited offensive upside. It kind of depends what you want in terms of a defensive stalwart. DeKeyser is the better skater with a better defensive stick. MacWilliam is more physical and better along the boards and in the trenches, he is also fearless and more than willing to stick up for his teammates. Both have a very good first pass out of the zone, but will never be mistaken as puck-rushing, offensive defenseman.
I would say MacWilliam's potential is a 5 or 6 defensive dman, while DeKeyser's is a 4-5 defensive dman.
Don't get me wrong, DeKeyser is a good prospect, but the hype around him is because he is the best player in the NCAA that is undrafted. Most of the best players have been drafted.
I watched him play about 10 times the last 3 years and he hits hard....his body positioning on the rush is outstanding at the NCAA level....lets see how he adjusts to bigger fast players. Should be fun to watch the balance of this year and see how he does.....he could really throw them in Jr A.....