As a young sushi eater i fell in love with Ru San's. There is a lot to love about this place- they have a huge and creative menu, they have a large selection of dollar rolls, and they have a high energy staff that is entertaining. However, as the years have passed I have fallen out of love with Ru San's. The main problem I have with this place is that their health code rating has fallen (more than once) into the 70s and that is just gross. One time they were reportedly docked points because food had been picked-up off the floor and then served. I have also been there before and seen that they weren't refridgerating all of the fish (I'm talking stacks of crab sticks just sitting out on a table, and they weren't about to be used). If this doesn't dissuade you, my friends have gotten sick several times after eating at the Nashville location.
EDIT: They have recently remodeled and I was quite impressed with the lunch buffet. I checked and the health code rating was above a 95.