Avantages
The work atmosphere is awesome. There is a heavy emphasis on work-life balance so you never feel overly pressured or stressed out. The people are some of the most laid back and easy to work with people that I've met in the hypercompetitive software industry.
Inconvénients
No matter how you dice it, few people will think that financial software is a "sexy" thing to work on. It's difficult to relate to the product unless you are a former accountaint. Furthermore, I worked on Quickbooks, an business software package, which is even harder for me to relate to than quicken or turbotax, both of which I have used. Also, having worked at a startup after Intuit, I realized that the pace of development at Intuit is pretty slow. I think this is a result of the bloated, old codebase, the size of the company, and the nature of shipping desktop software. In my experience, the downsides of Intuit are systematic to its particular field and not necessarily a fault of management or how the company is run.