Pros
At Avanade you have the ability to be exposed to the entire spectrum of Microsoft technologies, often before they hit the Alpha or Beta release stage. For example, we had teams working on the innovative MS Surface product for a solution expo before the product was officially announced to the public! There is also a great focus on certification and education. Also, Avanade will help you get what you want out of your career as long as YOU drive it and make opportunities for yourself.
Cons
Engagements are heavily based in technology, and projects often lose sight of the bigger strategic business impacts of their project efforts. Engagement management must continually balance technology against the strategic business drivers for their projects, and Avanade's senior leadership occasionally doesn't do a very good job of communicating this to customers (which is something that Accenture does remarkably well).