Yes, I did. I stayed over one night in Seattle and woke up quite early on the day.
Maybe, I had to wait for 30 min or something before they opened. Still there were 10 more people in front of me. Oh, I believe that you have to have 2 photos. The interview took maybe 10-15 min. My visa was expired, so I got lots of questions but if your current visa is valid and you have job authorization from Human Resources, you shold be ok. Even I made it. You can do it! Good luck.