Funny enough I was eating a Sumo as I came across your comment. They are certainly very tasty, but for the price (which is high at least here in Ohio) I much prefer the tartness of a traditional in-season California satsuma.
I highly recommend trying a cold Sumo. Refrigerated sumos are a bit of an aranciata vibe.
Sumos are bright and brightly flavored fruit often have a better experience when chilled.
All the California satsumas I can find here in California have all converged on the dekopon/Sumo taste and form. It’s confusing because the satsumas on Google images are still mostly the round ones without the bumps.
The prices vary wildly. At the end of the season I can find them in some ethnic grocers for $0.33 a pound while right now they’re $1.50-2 a pound. When they were first coming out years ago they were $4 a piece at Trader Joes.