Pros
The culture was one that pushed for excellence and innovation. BP management listened to us Senior staff members and let us do whatever we needed and however we wanted if we could show it would reduce risk and/or lower operational cost. They insisted we maintain a good work life balance so if we had to pull long weekends or evenings as DBAs often do they insisted on giving us comp time on other days. I never once worked more than 80 hours during a 2 week period in my 30 months there. They let us bring on staff in India who could do most work during off hours for us which helped the work life balance even more. Pay was very good.
Cons
The only real con was suffering from fallout of the Gulf Oil Spill. The reason I'm not there now is budget cuts due to having to pay for that. This was tied as the best place I've ever worked and I'd gladly go back to that team again if the compensation package was similar to last time.