Pros
Great benefits, decent pay, interesting industry, phenomenal networking opportunities, willing to train new hires. Friendly people to work with. Best in the industry. Overall I recommend Graybar especially to young professionals looking to start a career in sales, customer service and supply chain management.
Cons
Your experience depends almost entirely on your manager. Does not use the products they sell (I.e. sells LED lights but has old fluorescents in offices). Typical office politics apply here. Change is very slow (and change is important to stay alive in most industries).