Pros
Each agency is owned individually. This is good and bad. Allstate has so many resources to help with policies and quoting. This is a reputable company so the products your selling are ALMOST worth the premium. The company is always trying to be the first in the industry to introduce new products.
Cons
Allstate is notoriously one of the highest priced companies. Selling the value becomes increasingly difficult when their "ideal market" gets smaller and smaller. While they are usually the first to introduce new products in the insurance business, they are also the first to add more rating factors which often leads to even higher quotes. If you have a good agent willing to purchase leads, it's great. If your agent doesn't offer leads you'll see inconsistent numbers based on the market and rate increases in the area. It's always a hit or miss numbers game.