My first lobster roll was in Maine, some years ago, when I had barely begun to understand that lobster could be amazing. It was lightly seasoned with mayonnaise, lemon, and pepper. The bun had been lightly buttered and crunchy on the outside, but soft and absorbent on the inside.
This lobster roll, which Sam's Chowdermobile has brought back to a bit of popularity in the Bay Area, is many of those things. The lobster is juicy, with many large pieces of claw (not as much tail, which I prefer). There are pieces of celery (which I detest) interspersed between the giant hunks. There isn't much to the seasoning of this lobster roll, though I am sure it could use a small amount of mayo for contrast and for making the smaller bits stick together. Overall, the full bite of the roll was difficult, due to the fact that it was stuffed to the absolute extremes with meat. Once I had eaten some of the larger pieces, I bit into it for a "perfect bite". Combined, the buttered split-bun (which is rare on this coast) with the luscious lobster, the crunch of the celery (which I mostly opted out of), and a bit of mayo that I spooned on myself made the quintessential lobster roll bite.
Don't be discouraged however. I'm judgmental because I have actually eaten one of these from the coast where these are the stand-by. However, for a West Coast version, these rolls are exquisite and definitely worth hunting down this truck for.