Ventajas
Lots of smart people working on some pretty cool projects. Move towards SOA definitely opened up a lot of opportunities for learning within engineering. Pretty open collaboration with minimal stonewalling between teams. Most people are passionate and energized by the product roadmap.
Desventajas
Not many advancement opportunities for individual contributors. Over time, as team leads grew into Directors, members of technical staff only got to senior level, and senior got to principal. Relatively flat reporting structure worked great up to a certain size, but at some point the company outgrew it. Until recently, comps were not keeping up with the market, and new-hires (some through acquisitions) were coming in with inflated titles and packages. This also significantly diluted the culture.