I hate that RA is the only sushi place on Mill. The bar is pretty good, and the happy hour drinks are decently priced. But the sushi quality is very low.
Be ready for loosely rolled rolls, funky smelling raw fish, and long wait times. I must say that in the past year or so, food quality has especially worsened--don't know if they switched suppliers or management or what.
During happy hour time, the bar is pretty fun but it is a very strangely shaped restaurant not conducive to large groups (unless you go wayyyy in the back) and the noise level is pretty high around the door. I would suggest Rula Bula happy hour over RA, or even Gordon Biersch.
Stay away if you love sushi.