Minuses:
1. Oh god so slow
2. Not a lot of room. If you're getting on at Fremont you should be prepared for a wait.
3. Covered in advertising so you can't actually see the city from the bus.
Pluses:
1. Pretty comfortable for a bus!
2. Air conditioned!
3. Cheap 24 hour passes. Make 3 trips and you have your money's worth.