Okay, so I am a self confessed big fan of Pearl's Oyster Bar. Been many times, love the place (especially at lunch when I really enjoy sitting at the bar at about 2pm and watching the sun play across the buildings on Cornelia Street). I always enjoyed Pearl's lobster roll tremendously, along with many of their other specialities.
My wife suggested we try Mermaid Inn last Friday, and we walked in and sat at the bar without a reservation. The food across the board was absolutely delicious. I ordered their lobster sandwich - and was absolutely knocked out. Now, we can argue the merits of Pearl's hot dog bun vs. Mermaid Inn's hamburger bun all day. But I'm here to write about the quality and flavor of the lobster itself. Much, much more flavorful than at Pearl's (I cannot suggest why this would be, however). I can say that the lobster was held together with far less mayo/dressing - perhaps the flavor of the lobster was allowed to shine through more because of this.
I still love Pearl's and will be a regular customer. But Mermaid Inn has the better lobster roll.