I've been to Merchant on two separate occasions now and I have to say I'm really torn about what rating to give this place. To be clear this more of a 3.5 star rating but I don't have that option.
The first time I came I ordered about 8 oysters since they were half off during happy hour. All of which were delicious and reasonably priced for half off. As my main course I ordered the grilled cheese. It sounded amazing as I read the description but it fell short of my expectations. It just didn't blow my mind or make me wish I could have it again. After that experience I was really on the fence and would have probably only given it a 3 star rating at most.
My second experience I went on a Sunday for half off oysters. I ended up just ordering about 15 oysters and enjoying just that with some rose outside. I love the toppings options they have for heir oysters. It allows you to switch it up so you aren't eating 15 of essentially the same thing. I would have rated this experience a 4/4.5.
If you are looking to get oysters I would definitely suggest going during happy hour or on Sundays. The oysters are pretty expensive so I personally wouldn't have ordered them half off. I would also suggest sticking mainly to oysters. My friend ordered a lobster roll and she wasn't impressed with her meal either. She wasn't asked if she wanted it hot or cold and she wasn't asked if she wanted the mayo. She didn't see that it was extra for mayo on the menu so her roll was pretty bland.