We went to Quahog with 8 people based on rave reviews here and on Yelp. Most of the food was pretty good - fried cod & chips, pasta, pork sliders were very good. I'm not sure why people raved about the lobster roll. Yes, it had a lot of lobster, but the lobster was kind of tough and didn't have much flavor except for the lemon I squeezed on.
Though we liked the dive bar, nautical atmosphere, we found the loud TVs kind of annoying.
I would try it again as there aren't so many good restaurants in Falmouth.