NHL Game Center is awesome. I can watch 4 games at once on my PC. I can watch a game on my iPhone, iPad, Apple TV, Sony TV, Xbox ETC.....I have Comcast Blast (up to 50MB) and rarely have an issue.
NHL Center Ice on DTV is pretty limited and had it last year, I only have 1 box with DTV so I can't watch the game in my other rooms, but with my apple tv's that I have in other rooms I can watch it with NHL Cente Ice