Pros
Exceptionally kind environment of talented people who are always looking to grow their skills. Accepting of folks from different backgrounds and always aiming to deliver excellence in their work. Lots of interesting projects for large companies. They are experts in Microsoft, even owned partially by them. Their nature as a joint venture with Accenture means access to working with Accenture's larger customer base as well as Avanade specific work. They were the kindest firm (including my bosses!) I ever worked (up until this point) with and I will say that to my grave.
Cons
It doesn't matter how long you've worked with the org or your overall standing with leadership, Operations will remove you from the employment rolls if business goes bad enough, without much advanced warning. That's the biggest con. Other cons are: They toe the MSFT line exceptionally heavily and really only prioritize education to be line with MSFT certs and selling points. So for a holistic technology picture you'll need to do that on your own. Also, as a joint venture between Accenture and MSFT, you end up working on a lot of Accenture projects which can be difficult at times.