I just thought I'd add my MCAT taking experience from yucky land...
I took my test in a cramped community college classroom, which just happened to be adjacent to another classroom which was also in "session". This neighboring classroom wasn't an MCAT classroom, so it was a very noisy classroom. The professor kept on rolling the blackboard back and forth and the students laughed, loudly and frequently. This went on for the majority of physical science section. I did terrible on this part...perhaps it was because I was in the very back of the classroom, next to all the noise?
My proctors were way too lax...I was actually hoping for some NAZI-esque proctors, to keep things running smoothly and on time. They ignored the food, the timers on people's desks and whiteout during the writing samples (not that it bothers me, but when the hell would you have the time to use white out?). Oh yeah, and did I mention the cell phone ringing during bio? It was utterly fantastic. There weren't enough left handed desks, either, for all of the lefties. To top the great time I was having, the work-release workers were outside picking up garbage and making noises. WE also had a few lawnmowers going on right in front of our classroom. THe proctors finally closed the door after 20 minutes. It all was very obnoxious.
My friend had a silent testing room and the proctors made everyone put their phones, pagers, calculators, etc in the front of the classroom. She got done way earlier than me....and she tested at the same place as I did. It sucked.
There aren't too many options in the Sacramento area. Unless I go to the Bay Area, then I'm stuck at the same testing center.....hooray for me.
My advice: be prepared for anything--jackhammers, tornadoes, a marching band (someone on this board had some band practicing the day of the MCAT, I forget who, though), and any other obnoxious nosie. Be focused!