Pros
Have the ability to write and win any commercial account (middle market), great market share, good sales training if you are engaged, good culture in the office, great work-life balance, good incentives for successful producers, great resources for large clients, great support staff for producers when they are staffed up but there is a fair amount of turnover.
Cons
Easy to get lost in the organization because they are so big, decisions are made in corporate office which effect branches without regard to the individuals... profit over employees, they've gotten very large very quickly to a fault, over whelming amount of work/workflows for support staff to stay in compliance. They say they care about employees but they simply don't, there's a fair amount of "good old boy" structure in the organization.