1) Do you have mass transit where you live, and what type?
Yes, buses.

2) Does it get you where you need to go?
I'm not sure... if you're willing to walk several blocks on both ends, probably. The closest stop to my house is about 6 blocks away.

3) Does it run frequently?
Every 15 minutes during the workday, give or take. I think it's 30 - 45 minutes on "off hours"

4) Is the ridership composed of all classes of people? If not, is there a stigma for people who use it?
It depends on the part of town. Around the colleges it seems to be mostly students. Downtown, there's a lot of professional types. But there always seems to be at least one "less savory" individual.

5) Is it clean and safe?
In reality, it's probably safe, but I don't feel safe riding alone, especially in certain parts of town. As far as clean... eh... it's moderate.