Pros
Stability and overtime. If you want a job that's not going to go away overnight (provided you can avoid running into stuff and have a decent attitude), and want to make a lot of overtime money, this is the right place. Benefits are good as well. Management is fair. If you do your job and keep your nose clean, then you'll have no problems with management. Culture. When you get to know your fellow drivers, you'll feel like family. Sharing crazy passenger stories never gets old. You really start to relate to others who do this job.
Cons
Work/life balance. Prepare to have no life outside of work for the first year or so. New people get all of the worst shifts. You'll end up with 3-4 hour split shifts regularly (8 hours of paid work time, but split by 3-4 hours of unpaid time, leading to what feels like 12 hour work days). You'll get called in on one of your days off regularly, but if you like or want overtime, this isn't really a con. Work environment. Driving a bus gets easier every time you do it, but dealing with people never gets easier. Some days everything will go smoothly, and you'll feel like everyone appreciates what you do. Other days everyone will seem to be in your face. Most days it's somewhere in between. If you have thick skin, or want to develop it, this is the job for you.