Of course this place is full of tourists but if you've gone all the way to Furnas it seems silly not to at least try the cozido. Two of us shared the cozido for 1 person (they also offer a 2 person size) and the grilled squid. The squid was great. The cozido has several types of meats. All were tender but some were a little bland. If you go for dinner you can watch them pull the pots from the caldeiras at around 5pm, and I found the whole cooking process is interesting. If you go at lunch I believe they pull the pots around 11am-12pm. Would recommend making a reservation even in the off season. It can't hurt and you never know when they will have a tour bus full of people packing the place. They were booked the first night we tried and 70% empty the 2nd night, when we actually ate there.

I wanted to eat the traditional cozzido so we decided to give Tony’s a try. The atmosphere was a bit lacking but the food and service were very good! Good wine too!

We HAD to try the cozzido, and Tony's is supposed to have the best. We made reservations in advance (As we were told you must in order to have the Cozzido).
We asked for 7 pm, and were told that they couldn't do that, but could do 7:30pm.
We agreed. We showed up at 7:30pm, there were only 2 other tables of guests in the entire dining room, Hmmm. Of course it was blatantly obvious to us because the blinding flourescent overhead lights lit every nook and and cranny of the restaurant.
The Service was ok, but it seemed clear they wanted us to "Order and move on".
2 of our party pre ordered the Cozzido, the other 2 ordered off the menu.
The Cozzido was rather ordinary. It was perfectly serviceable boiled dinner, but there was no smokiness, no sense that it was prepared in on of the volcanic Holes that we had viewed in our exploration. The Cozzido was just ok. not bad, but not anything I would say that you can't miss. If This was the "best", I cant imagine what the others are like. The Other meals were also ok, definitely not memorable.

Actually went to try the special stew made in the ground but it was obvious on arrival you actually need to order it a day before otherwise those that have done tend to get all that’s available. None the less we still had a great meals, the meat platter and the limpets we excellent, as was the service. We sat on the balcony and people watched as we ate. Good call.

While visiting the famous "furnas" in São Miguel, we, of course, had to taste the famous "Cozido das furnas", which was nice, but nothing too amazing, as it doesn't include some of the traditional cuts of meat that this dish usually has.
It is quite a busy place and reservations are required, I would say at least 48 hours before visiting. I, however, called during the morning of the day we were planning on going there and they had only a couple of spots available for early lunch, which wasn't what I was after. So they told me to come anyway, after 2 pm, and when we got there, the host worked his magic to find us a table, which was great! Even though it is a very busy place, service is good and waiters are quite friendly.