I have been here four times now, and am somewhat surprised at the existing reviews. I will admit that we were not really watching our wallet, as we have always come with discounted on-line deal certificates.
Koto is a contemporary Western-style sushi restaurant. You go there for the same reason you go to see a rock opera: you don't need to be an expert to appreciate it, because it's not subtle. The real stand outs here are the creative (but pricier) rolls that successfully incorporate bold flavours (e.g. mango, jalapeno) into good quality traditional (eel, tuna, etc.) and Western (e.g. lobster) fare. These rolls do not need soy or wasabi to feel complete.
The rice has been consistently excellent in our rolls. I will agree with a previous reviewer that the roll ends can be a bit messy, but not egregiously so. The service has always been acceptable for us, and (at least currently) they actually have Japanese people on staff...a rarity in Calgary.