Pros
In it's infancy, MySpace was a great place to work. There was a great balance with product and strategy, and it appeared that there was a clear vision of where the company was headed. Additionally, due to the notoriety of being the largest social network company (at it's time), it was a great resume piece, as well as made for great conversation with chief marketers of large brands.
Cons
The only downside was that Senior Management completely lost it's vision, as well as not being wise on it's hiring practice. Towards the end of my employment, MySpace was fairly bloated as far as staff goes, and that staff wasn't the most efficient group of people. They had no clear vision, and had to continuously try to reinvent the process on an ongoing basis which contributed to poor morale amongst the team.