I've been to Hyakumi multiple times and the food quality has been pretty consistent...just right about average. Sushi grade is average, Teppan Yaki is average, service is average. Nothing's strikingly notable. Though Hyakumi does have an extensive menu items to choose from.
Comparing between regular sushi dining and Teppan Yaki, I would recommend Teppan Yaki over the sushi menu. With everything being just average, it will be more entertaining to look at the chef cooks in front of you than eating just average sushi. Also, request for indoor seating rather than at or near the sushi bar. The inside of the restaurant is very nicely decorated with a Japanese garden theme.
Three stars for everything being just average.