Granted, I did not eat at every sushi restaurant in Osaka so I will refrain from any hasty generalizations. However, I did go to the Anthony Bourdain's sushi spot, Koyoshi as well as Jenin and two other highly regarded sushi restaurants. I will also say I went a bit cutting edge as I leaned more toward fish not present in the US. However, at home I enjoy all types of sushi.
Anyway, I did not like one bit of sushi I ate. The old stand bys like tuna, toro and salmon were no better or fresher then what I can get at home. In fact the sushi tasted "fishier" then at home which may indicate its freshness and may be interpreted by some as tastier.
I know all sushi served in the US with the exception of tuna is prefrozen. Perhaps that takes away some of the edge which I am more acustom.
Abalone repeated on me from days.