There is no doubt that the making of sushi is not just a culinary trade, but it is also regarded as an art perfected over a lifetime. Below are some memories and points that highlight various things that make good and bad sushi bars. Things like shop conditions, ingredients quality, etc., but most importantly, the sushi chefs themselves are the ones that stand out as affecting the good sushi vs. bad sushi comparison.
"Bad" Sushi Bar 1: Tokyo, Japan -- A local place caught my eye as a cheap and quick means to end my weekly sushi craving. Unfortunately, more often than not, "cheap" and "quick" should be taken as red flags when it comes to sushi. The restaurant immediately smelled of fish upon entering and after taken my seat, the counter smelled of cleanser, a shear sign that the meal would not go well. However, hunger and convenience overpowered my reason and I started to order.
Every order seemed to take 5 minutes and in my opinion way too long to serve one person out of half a dozen customers, most of them already on their way to the register. I could tell right away that the fish was spending way too much time in the hands of the chef, and it smelled and tasted faintly of other types of fish -- meaning he wasn't doing a good job of wiping his hands in between orders. After a few pieces, I decided to cut my visit short and finish up with a piece of sushi that I thought no sushi place could get wrong -- maguro nigiri (tuna sushi) -- but again they failed me. Despite a 3-4 minute wait (now being the only customer in the shop), the maguro was frigid and was still frozen in the center despite being handled for so long. I paid my (short) bill and left vowing never to return (I wonder if the 6 or so patrons before me were thinking the same thing as well...).
Some points to take away from this experience:
A sushi restaurant should not smell especially fishy as that either means the ingredients are not fresh, or they've (unlikely) overstocked on oily fish like mackerel or (low grade) salmon.
Residue from overuse of cleaning chemicals interferes with your sense of smell, partially ruining the sushi's taste -- giving those part-timers extra cleaning duties throughout the day didn't pay off.
Sushi that spends too long in a chef's hands runs the risk of coming into too much contact with heat from the chef's hands and human body oils, which can reduce the freshness of the fish and interferes with the overall taste of the sushi. It might have been fresh at one time, but it only took 5 minutes to ruin it.
Sushi ingredients with the exception of bintoro (bincho maguro) should not be ice cold because not only is it akin to eating a sashimi popsicle, it brings into question the freshness of the ingredients (if it's still frozen, it was not procured anytime in the near past).
"Bad" Sushi Bar 2: An even smaller place in Shinagawa, Japan stuck out as having a fresh made-to-order menu at a reasonable price. I gave it a shot but was turned off for different reasons from "Bad" Sushi Bar 1. For example, shortly after ordering, I could see the sushi chefs who were on standby smoking in the kitchen. Just imagining the tobacco smell and nicotine stains on the fingers that prepare my sushi was enough to make me a bit wary of what I would soon be feasting on. I also noticed that all the fish to be used for sushi was pre-sliced and placed on metal trays in the transparent refrigeration units on the bar. I thought this a bit of a let down as I want to make sure the fish is taken from a fresh "slab" of tuna and so on.
My customized sushi platter was made in record time and was picture perfect. While I appreciate speed when being served at a restaurant, I also know that it takes skill and care in handling the ingredients to produce a good product. The sushi looked like works of art, but they were very fragile.