Muddy York, like many local microbreweries, has gone the "tasting room" route. This is an easier license to acquire, but imposes certain limitations: they can't serve full pints and they have to close relatively early. They're also not interested in being a restaurant (with all the health inspections and the like that that implies), but they're fine with you bringing food in. They list a closing time of 8 PM, but it seems that this is more the time of last admission - if you're having fun, you can leave as late as 9 PM.
Here's the rest of the checklist: Patio, yes; bottle shop, yes; flights, yes (four for $10); nice ambience and not too loud, check.
They're right in the middle of an industrial area in the up-and-coming St. Clair and O'Connor neighbourhood: you aren't finding them unless you're looking for them. And I'd recommend looking.
They seem to be putting an effort to maintaining 12 active taps, which is excellent: you'll always have choices. Of the beers I tried, I really liked the Diving Horse Pale Ale: sadly, they didn't have it bottled at the time. The Storm Glass IPA was fairly nice. The Muddy York Porter was an experience: lovely chocolatey nose, taste of coffee and chocolate, afternotes of cereal(?!). I've been known to taste things no one else could, but I was actually backed up on that really strange aftertaste. I wasn't a fan of the stout, but pretty much everyone else liked it. In fact, all four of us came away very happy with the beers we'd tried: definitely a good experience.
photo: My flight at Muddy York
photo: The beer menu on the day we visited
photo: They go for a 19th century slightly industrial aesthetic, and the taps are kind of awesome: