Happen to have the Chirashi at both Toraya and Oiishi this week which allowed me to do a nice side by side comparison.
Price: $12 at Toraya for lunch vs $25 at Oiishi for dinner. At first I balked at the $25 price at Oiishi but was really in the mood so I decided to see if it was worth it.
Miso: Every time I have miso soup at 99% of Japanese restaurants I cry a little inside. Why oh why do restaurants not make homemade dashi? It's cheap, easy, and tastes so much better. But alas, both used instant dashi. A draw.
Service: Oiishi, with four chefs working, had my Chirashi out in 5 minutes from when I sat down (granted I ordered 5 minutes before while waiting for a table). Toraya, with one chef, took a painful 35 minutes and it wasn't even that crowded inside.
Rice: Toraya wins this for me. Most sushi rice in the states I find too bland or too sweet. Toraya was balanced but with a slight hint of vinegar ie. just the way I like it. Oiishi was too sweet and had undissolved sugar in it, a huge miss.
Presentation: Oiishi, by a hair. They both came out in traditional Chirashi bowl with an eye towards presentation. Oiishi had a nice flower on top and had a wide color contrast.
Selection of fish: Oiishi definitely offered more, but was also twice as expensive. I believe Toraya was eight different types and Oiishi was twelve (approx). Neither offered anything beyond the standards/classics though. Oiishi by technicality.
Quality of fish: Oiishi's fish definitely seemed fresher, with the exception of one fish which had a distinct iodine taste to it. Toraya's was fresh enough, above average, but not sparkling fresh. Oiishi wins this round.
Cut of fish: Here is where I really enjoyed Toraya. Oiishi's cuts were just way too big. They were long and twice as thick as a standard American cut. Each piece was the size of two of my fingers together. While for some people this might be a pro, I found it detracted from the enjoyment as so much chewing was involved it took away from the flavor. The chef at Toraya, on the other hand, did something interesting, he cut the pieces in half so each piece was the size of three quarters stacked on each other. While smaller and squarer than what I'm used to, I really enjoyed it. It allowed me to savor each type of fish in a short punchy bite. The slicing was also very well done and everything was extremely tender including the octopus.
While I enjoyed both, I have to recommend Toraya (which was recommended to me on Chow). Cheap, delicious, authentic. Feels just like Japan.