I have visited Half Shell several times and always have had a decent experience, with large groups and just for 2.
Last night was a particularly nice experience. My boyfriend had a restaurant.com certificate so we decided to have a nice date. We started off with their new chilled seafood platter for an appetizer - king crab legs, shrimp and oysters on ice. YUM. I had only had the M's oysters before but these were huge and fresh!!! I will have to go back and just get oysters next time!
For dinner, I had the tuna tartare appetizer (I am a cheap date) but the boy got a 12 oz ribeye and a lobster tail (high roller) - service was very attentive and drinks were refilled regularly.
After the meal, we slipped into the bar area to watch the end of the Mavs OT game. Several bartenders asked if we needed anything, but we just watched the end of the game and left. I would definitely recommend this for a casual seafood meal or sports-watching at the bar.