Wow. I just realized I have never Yelped about Hiro. Way before Yelp, I reviewed Hiro on some other website, and I think what I wrote ended up on an award displayed on the restaurant's wall for being "best sushi" in Phoenix.
Anyway - About the food... First and foremost, the fish is flown in DAILY. Not once a week, not every other day, DAILY. Ask what is fresh that day, and you are sure to get the freshest fish in town, even on a Sunday!
I love sashimi - no rice, no roll, just raw fish - and Hiro's is the tops. While they haven't had it in a while, the Striped Jack is my all-time favorite, but give me any sweet, buttery, or somewhat firm fish from Hiro, and I am in heaven.
BTW, don't let the strip-mall location scare you away. What it does say about this oh-so-awesome sushi bar is that it is a place to get damned good sushi, not to be seen. If you want the typical Scottsdale bar scene quasi-japanese restaurants better known for happy hour specials than fish, don't go to Hiro. If you want the best sushi in the Southwest, take a drive to Hiro.