Pros
Extremely Agile - multiple meetings keep you on your toes, providing an avenue to ask questions and update status. On-going training to become MS Certified in multiple areas (for the lucky permanent employees) keeps this place busy also - and also a strongly desired employment perk at least to me. Despite my Cons below and such varied personalities and stress there - I would still consider this one of my most desired 'want to work for' companies I have worked at; overall those I worked with were fantastic people!
Cons
The rapid pace of assigned tasks can often overwhelm - especially when expected to complete an assigned task in the estimated time. Estimates for adding new tools often did not consider problems implementing due to lack of tool support or usage info. I often put in many extra un-billed-for hours in an attempt to learn the new tools in hopes of making the estimations. I did not mind, after all learning is important as demonstrated by some tasks being finished in 1/4th the assigned estimate...