I live in Los Angeles, so I could understand your situation, LOL
Anyway, the sushi you speak of isn't bad for you, but I wouldn't say it's the greatest thing for cutting. It's very tempting because a whole plate full, like 8 pieces, is only about 300 calories, no fat, and tastes great. and that makes it a good choice for when you HAVE to eat out.
However, a meal of sushi is mostly carbs, a lot of salt, and very little protein for the price ($8 for a plate of 8)
in my opinion, sashimi, just the raw fish, is better on a cutting diet.