Pros
It's a great working environment and a solid, stable company. Sysco does seem to genuinely care about their people. My personal experience was a good one from an employee's perspective. Pay at Manager level and below is below average, however if you can rise to upper level management salaries become more competitive. Great place to get some solid experience at a company that has a great reputation.
Cons
Advancement can be hard to come by, there is a sense that most advancement decision are based on tenure and not qualifications. Pay is lower compare to equivalent positions in other, more profitable industries. Pay in general is lower then other companies you'll find in the area of the corporate office. Being based in Houston, TX Sysco has a hard time competing with many of the companies in the more lucrative oil industry.