Prós
Excellent work/life balance, good compensation, and training! Every 2nd Friday is off with their 9/80 schedule. Some smarter folks avoid meetings on any Friday, thus you never know what schedule they are on and if they are ever in the office on Fridays. Most of the work is done through contractors, thus in reality it is not clear why an oil company would be penny pitching their employees. And Shell does not! A million here, another million there, thus it is far more important to ensure that people are happy and do not squander the money on contractors in order to retaliate.
Contras
Big and bureaucratic, but nothing is perfect. The IT systems are quite dated and crappy, run by some outsourcing shop in India or wherever. A lot of dead wood, that is quite proficient in the appearance of being highly busy at all times.