Pros
Loved working with many of the tax-preparers at H&R Block. There is definitely the opportunity for advancement - as a receptionist I was offered the opportunity to take a tax class and start working toward becoming a tax preparer. As an employee, you can have your tax return done for "free" by a co-worker ("free" because it is put on your W2 as compensation, so you're taxed on it).
Cons
Corporate doesn't seem to listen to the people running the office. There are alot of expectations from Corporate, but those making them don't seem to understand the reality of the offices and don't seem to care about what their employees think. Not much opportunity for good pay (unless you're doing taxes) or hours after tax season. Your also made to take 8 weeks off (unpaid) so you're still a temp employee and benefits are not offered.