Parking and wait: like clockwork, the lunch rush begins at 11am. If you can arrive before/by 11, you'll little to no wait. Otherwise, you may see long lines, but the food service is very quick so you won't wait for long. But the wait isn't your biggest obstacle: the parking situation is. Sometimes there is a line to park, too....
Food: I have always enjoyed the food when I visit! I like the sashimi and tempura the most. I want to try the stewed fish heads and Binbi meshi next time! I think the sashimi pieces would be better if they were smaller, but it's still delicious.
Service: I'm not sure if my treatment as a customer is affected because I'm a foreigner who doesn't speak fluent Japanese, but I've always felt like the staff think talking to me is めんどくさい.
Tl;dr: timing is of the essence, the food is worth it