Pros
Face it, it is NASA. They do awesome stuff if you can get on a good project. Ames is known for having the projects that may be a little too crazy or risky for other centers (at least that is what I picked up when I was there) so it is a good place to see what NASA could become given the chance. Really interesting work is coming out of there. The projects do take a long time and have a lot of red tape since it is the government. You will also encounter the civil servants waiting out their time until retirement but they tend to at least somewhat care and will pass on tribal knowledge.
Cons
The flip side to working for NASA? Welcome to the good ole boys club. If you are a female engineer prepare to be stared at any time you walk outside. Prepare to be questioned first and trusted later. Prepare to be ready to hold your own at all times. I now understand why women don't stick around, it isn't worth it in my view. Until they embrace diversity and teach the guys about working with women, run across the street to the other places in the valley. Also, pay is much lower than you can get anywhere else. Start looking at McDonald's for a second shift if you like something higher up than a cardboard box and you have only a BS.