i find most neighborhood restaurants make either poorly executed sushi, or use poor quality fish, or a mixture of both, while charging astronomical prices. I really think most people don't know what good sushi is.
Most of the cheap places will drench their rolls in sauce or non-fish fillers. the higher end neighborhood places will do the same but maybe use some more fish. Invariably, most if not all of the restaurants mess up the rice, which IMO is the most important part of sushi. as someone else said, sushi really should just be fish and rice, not all the sauces and other "creative" stuff that goes on there.
While I have no problem with creative rolls, I just hate the places that make you a "dragon" roll and have little to no fish in it, or crappy spicy tuna and then charge $18 for it. I can get the same quality of sushi or better at wegmans for $10 lol.
In my town, sushi for two costs around $80 for frankly mediocre / crap sushi. I can go into philly to say morimotos and pay the same price or 20 bucks more and get very well executed sushi. There are some definite stand out places though that know how to make the rice correctly, make the basics great, are creative still have a decent price. definitely few and far between though. in japan, you can fill up at a conveyor belt sushi joint for $15 bucks and even that has better quality than most places in suburbia usa.
I have no problem with using or eating frozen fish. I think it's much safer too. My wife and I did a cost analysis and realized that we could make sushi at home for less money and better quality than going to a mediocre sushi restaurant if we ordered fish online (you can even get bulk alternator sized fish online too!). We can make the slices of fish as thick or thin as we want. Sure there are some fish that taste better fresh, but the basics like salmon, yellowtail and tuna are almost always frozen at the restaurants anyways and we stick to making basic nigiri and chirashi with some rolls.