I live in SF and I've done the race.
It starts at like 5:20 AM, and it's pretty hilly, and it's not cheap. The hills aren't super long or super steep, but if you're praying for a flat section after mile 4 you won't really get one until the final few miles. I think the hills add 5-7 minutes to your time. I saw some webpage that claims it only adds 2.5 minutes, but that's under optimal conditions -- the nature of the hills (lots of short steepish ones breaking up the course) and the nature of the marathon means it adds more than that.
I don't know how fast you're planning to run, but if you look at the past results you'll see that it's pretty thin at the front, 2:50 is 15th place. Which means if you're running much faster than 3 hours then you're going to be running a significant portion of the course on your own.