TL;DR: Inconsistent food, at a high price. When they're on, it's great. When they're off, you spend $30-$40 per person on mediocre food. Good atmosphere, good service, good beer.
Full review:
Based on my two trips to the Big Grove, it seems to be hit or miss.
The first time I went, around January of 2014, I was extremely impressed. I had pork belly as an appetizer (amazing) with a Dogfish Head 90 minute to chase it down (the beer selection is pretty great). For dinner, I had a perfectly cooked steak (don't remember the cut), served alongside gnocchi. Everything I ate was relatively simple, but they executed perfectly on the local, farm to table ingredients (they're proud of that here). Service was fantastic.
The second time I went, in July 2014, the food was very disappointing. The steak was solid again, but it was served alongside one of the most bitter, poorly cooked broccolini I've ever had the displeasure of tasting. The pork tendorloin was chewy, definitely do not recommend. And this time, the pork belly appetizer was served differently, as a salad. I think it's pretty difficult to screw up pork belly, but they managed to do so. It tasted as if it were cooked a day ago, and it was difficult to find much pork belly beneath the greens.
Service was tremendous on both occasions. Our water and popcorn (the popcorn is great) were refilled consistently, and the waiter seemed to take pride in the food.