Pros
They are very flexible to keep good people so even if you have things going on in your life, they will really work with you to find a way to make it work for you. Lots of people work from home some of the time, work schedules different than 8-5, but still get 40 hours in, or work 30 hours a week except during tax season.
Cons
They do have required minimum hours during tax season, like all CPA firms, that really limit your ability to balance anything with work, especially a family or life.