Sushi is always a tough one for me in Charlotte - I have found places I like but none that I love...and Koi to me is just ok.
Koi is in the neighborhood so I do frequent the place with the neighbors - the food is tasty nothing great but nothing bad, however it seems like the sushi takes forever to be made. I haven't once been there where the entire parties food has come out at the same time.
I also think the sushi pieces are very small compared to some other places I've been to in town.
On a postive note the staff is friendly they do take-out and have an extensive menu for sushi and chinese food.