Vantaggi
I worked under two contracts (an 11 month contract-cur short, and a temporary one month contract). Management is very open and welcoming of ideas. Communication of best practices from those who have had success is encouraged. Most of the reps on my contract were surprisingly high quality. I learned much from my colleagues. ProPharma uses (IMO) more of a "Moneyball" approach. They hire great people in the later career years whom other companies might overlook but bring fresh ideas to the table...especially when they are joined into a team.
Svantaggi
Not sure why they don't have more contracts from pharma companies. My contract was cut short despite the gains made. The companies who contract with ProPharma need to respect and learn from the vast experience they have and hire. Pay was not particularly high but the incentives were more integrated into the culture of the company.