Pros
I moved to Seattle right out of college to take a job in the risk management (anti-fraud) department. It was a little intimidating at first, with a learning curve like any job, but after a few months I was doing a lot of productive work. I was given significant responsibility early on and after 3 years, I was the team expert on several major systems. Work/life balance was pretty good in my department, though I heard stories about others not being as good. Definitely ask your potential manager about pager duty - everyone has it, but it's much worse for some. Eventually we got 12x7 India support, which meant no more being woken up for nighttime production issues. As far as working hours, I put in my 40 hours a week and went home. No weekend work except for the occasional on call. I rarely *ever* put in any overtime, with the only exceptions being around the holiday season, which is considerably busier for most people. My manager was very good about respecting the importance of family and other personal needs. Work schedule is ridiculously flexible (sometimes a bad thing) - generally you could come in at 7 am or at noon, as long as you put in your 40 hours, and no one is counting either. Benefits are pretty good. You get a bus pass that gets you free unlimited bus rides, including commuter buses. Some pretty famous people come to give talks/book signings for the employees. Parking at Union Station is free after reimbursement if you can get one of the cheap enough lots. Not sure what the situation will be after the move to South Lake Union. Pretty easy to get promoted within the SDE levels (1/2/3). I think lots of people get promoted from 1 to 2 in the first couple of years - this carried a $15k raise for me. Technology is fairly up to date compared to other companies. You get a laptop which you can take home with you. Lots of super smart engineers. Casual, informal work environment is nice.
Cons
Operational burden can be rather high; by that I mean you can end up spending a lot of time doing things that are not related to software development (reading lots of email, answering questions asked by employees in other areas, pulling data that your manager needs, metrics, etc.)