Pros
The people are the best and worst part of PMI. Many are happy to collect a paycheck and do enough to not stand out for either being too ambitious or too effective. Many come to PMI for the sense of purpose and mission and find a place where they can become part of something bigger than themselves.
Cons
The Project Management Institute, until recently, did not require it's own PMO employees to hold the certifications the organization provides. This would not be a problem if PMI had continued to strive for a cultural meritocracy rather than an environment where multiple consulting houses operate at cross purposes without clear mandates and little accountability to either the membership or the professional corps. As a result, much of the best talent is stripped from the ranks and what passes for 'taking action' often involves the installation of a new executive and the reshuffling of people without clear purpose or intended effect.