The Group Health co-op here in Seattle has both fans and detractors. Doctor and hospital choices are limited and not always the closest. A local co-op is too small and financially constrained to meaningfully compete financially with nationwide insurance oligopolies if they choose to compete. College children could well be outside the coverage area. It cost more than other plan options at work, so I did not choose it due to cost and inconvenience. They have to cost-ration care for expensive things like liver transplants, requiring long fights with allocation boards if you want care. Co-ops are a toothless diversion concocted by congress critters in the pocket of insurance corporations. Single payer and even the public option have much more power to reduce costs and provide competition. Co-ops are an attempt to co-opt the role of a tiger by substituting a pussy cat.