I am rating this place primarily as a brewery and only secondarily as a restaurant since it is, after all, primarily a brewery.
How is the beer? Outstanding. Without a doubt this is the best American microbrewery, in my opinion. I have only tasted a handful of beers that are on par with the better beers produced by Great Lakes, and I have never found an American brewery that can consistently produce brews of the same quality.
My favorite beers are the Edmund Fitzgerald porter (my fav. beer in the whole world) and the Burning River Pale Ale...I'm also a huge fan of their Locktender Lager and their Conway's Irish Ale (in my opinion, the best Irish ale I've ever had, and it isn't even Irish!), but all their beers are good.
The food and atmosphere is decent...about what one would expect from a brewpub. I'd say the food is above average for a brewpub but nothing earth-shattering.
It's all about the beer!
Ahh I miss this place so much...I can't get their beer anywhere on the east coast and it is driving me insane!