We went to Bar Buca for brunch on a Sunday. It is definitely a popular place - the patio was already full when we went around 10:30am, but plenty of seats inside. When we left an hour later, the place was already full.
It was weird walking in since there is no reception counter, so I had to flag a waitress down to get a seat. Upon seating, the service was a tad slow and this was true from getting the order, getting the item and the bill itself.
We ordered a latte each, and shared the porchetta stuffed foccacia, and the bistecca tagliata (steak and eggs). The focaccia was a very decent portion, and it was delicious. We would have been satisfied if we just split that. The steak and eggs was presented very well and cooked perfectly - steak was tender and juicy, and we liked the sunny-side up eggs and greens with it.
Overall, the food here was great and the service could be improved. I would give this place a 4 star rating.