Just as a per-cursor I've only been to this restaurant for lunch and it's never been crowded when I go so service so for me has always been awesome!
This is the spot! I have been to Sushi restaurants all over the valley a lot of times you will hear a review that says "It's nice to get a decent restaurant in Gilbert", but this is the spot regardless of where you're at in the valley. It's very clean and modern with red and black theme that is just awesome. It's at least as good if not better than restaurants I've been too including downtown Phoenix or Scottsdale.
Their lunch specials are amazing all priced under $8 and includes things from Pho to a pork katsu bento to calamari tempura sushi rolls. I've tried almost everything on their lunch menu and have never been disappointed. This place is almost never busy for lunch so if you're in the area don't forget to stop in because I'd hate to loose this restaurant as my families go to place for lunch. Right now road construction makes people reluctant to patronize businesses along Power but fortunately Red Koi is located at a light so even making left hand turns into it or out of it makes it easy so don't let the construction deter you from stopping in!