This place is amazing it. The only place I've been to that can compare to it's sushi quality is Shimogamo, and Kampai is MUCH cheaper. Weather you want some basic rolls and nigiri or more "exotic" dishes its always fresh and delicious. All the non-sushi menu items I've had were also great. Their katsu is flavorful and succulent, some of the best I've had, although the portion isn't as large as some places.
I'd like to talk a little about the service because I'm surprised by all the bad reviews for it. First, if you sit at the sushi bar I think you can expect amazing service and a fun experience. Second, the table staff is a little less attentive, but in my opinion at most authentic asian restaurants you usually have to make eye contact or motion to them when you want something. I think its a culture thing, they don't like to "interrupt" your meal.
Finally, it's surprising to see how many people complain about the time it takes to get their sushi or how they had to wait 10 more minutes for their carry out. I've never been to a GOOD sushi place where rolls don't take somewhat forever unless you're the only one there. These people who are so concerned about time that they'd give this place a bad review should try Kona or RA, I'm sure their crappy quick sushi will be to your liking.
But if you're looking for top quality at a reasonable price... then relax, enjoy a hot sake and prepare for a flavorful treat. Kampai!(cheers)