Avantages
There are many. Autodesk has wonderful people and is working hard to keep a kind, balanced, open, and interesting environment. The offices are beautiful, the attitudes towards work / life and humane, the pay is good, and the products / customers do really amazing things. As a tech company, we're not slinging "ad words" or some next flash in the pan photo sharing app -- Autodesk technology really impacts the world around you and that's inspiring.
Inconvénients
There are few. Like any big company, sometimes projects or ideas can get caught up in tape, bureaucracy. Certain areas are hotter than others and move faster. That said, if you build good relationships and are influential it's not hard to get stuff done. This is a minor "con" for me -- I've worked at a handful of medium to very big companies and have driven more ideas and projects to fruition here than anywhere else.