Pros
Company is growing like a weed due to some really positive business practice changes in recent history. It's nearly impossible to get fired; this makes it a great company for someone who doesn't have a ton of experience but is a hard worker. Failing is seen as process of learning. Allstate is transforming from a 'gut-feeling' decision company to data-driven decision company. This means younger/fresher minds making big decisions. Great benefits. New senior managers are superior to those they are replacing. This company has a great future.
Cons
Old company that is stuck in its ways. Many of the managers were successful 20-30 years ago and have held on to their comfortable job for the pension. These managers don't want to rock the boat or risk their career on a new project, so things move very slowly. The top 25% of talent is not adequately compensated for their abilities. The top 5% of talent is promoted very quickly through the very limited management spots at Allstate. The next 20% of talent occasionally gets an analyst promotion (~10% pay increase and no new responsibilities) and maxes out their annual merit increase (~7% per year). This group could make substantially more at a start-up-style company. The best workers don't have much work-life balance, but the typical 9-5 employee does not progress in their career. At Allstate, you really have to choose between the two.