My experience with Buca's is limited to the St. Paul location.
The best thing this place has going for it is the service. Our waiter was very attentive and took care of our every need promptly. We also got in very quickly without a reservation (5pm on a weeknight.) We did not find it any louder or more boisterous than your average family restaurant.
As others have noted, it's a "family style" service, which means that the "small" servings are meant to feed 2-3 people and the "large" servings are meant to feed 4-6 people. It's brought out on platters and bowls, and you dish up your own serving. If your party doesn't agree to eat the same things, you're going to get WAY too much food.
There were three in our party and we ordered one small Bruschetta (good, fresh), one small Chicken Marsala (average), one small Tortelloni (gritty, doughy texture), one small Garlic Mashed Potatoes (average), and one small Chocolate Cake (very good). We learned that the small Chicken Marsala (that was supposed to be enough to feed 2-3 people) comes with only two pieces of chicken breast. For an additional fee, we were able to upgrade to an extra piece of chicken.
If you're in a party of three people, I suggest that you make at least one of your selections a "large" to insure that you get enough, and be sure to ask about the size of that entree.
The portions bordered on inadequate. The food was good, but not exceptional. The tab, however, was exceptionally large in relation to the quantity and quality. I would have expected one or both to have been better, for the price.
My opinion is that you can do better at The Olive Garden, and your party will get more variety. The only reason to go to Buca's is if you find the ambience and "family" experience to be worth the additional price.
Pros: Great service with friendly wait staff.
Cons: Smallish portions of average Italian fare at a high price.
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