Pros
Money is decent - average to slightly above average for the market. One of the few high tech employers in Arlington. My commute is under 10 miles round trip. Unless you are a Windows admin you probably have a good shot at a long term stable position. Recently updated cubicles. Decent raised floor datacenter. Building is supposedly tornado-proof. Based in Europe (France / Netherlands), so somewhat insulated from the currently crappy US economy. Big Olympics sponsor & IT provider (current China controversy is a downside though). If you don't want a high profile employer (nobody in the US has ever heard of us), then this is a great place to be.
Cons
Customers are mostly oil & gas & chemical related - lots of up & down swings in business, and no fun working for global warming culprits. Used to be Halliburton's data center, still have some of their business along with KBR (can you say, Iraq war crimes?). AO North America is a tiny piece of the company; Europe gets almost all the attention & money. AONA HQ is in Houston not Arlington, so they get most of the rest. Too much employee turnover, especially under the Windows admins group. Too much night & weekend work. No overtime or comp time for salary employees. Health & dental plans are not great (United Healthcare / Delta Dental). Only 2 weeks vacation per year, for first 5 years. Not that you can take all of your vacation anyway, once you get into the 3-4 weeks/year area, most likely - and you can't carry unused days over year to year anymore, either. Internal equipment is given short shrift compared to customers - network & backups are a constant issue.