Yahoo

• Very smart people; you can learn a lot.
• Strongly motivated team that is making an impact on the web.
• Opportunities to move into various roles with various levels of expertise.
• Incredible opportunities to work with lots of data and the most cutting-edge technologies in this area.
• For Flickr in particular, an incredible culture of very self-driven, highly intelligent, and socially able people.
• A renaissance is currently happening across the entire organization.
• Open culture.

• Dealing with some of the older platforms can be tedious and fall short of the cutting edge.
• Performance reviews are rigid and unfairly bucket employees.

You're doing great. The one thing I would pick on is the implementation of performance reviews. The feedback itself is great; however, I don't think the ranking is helping or necessary, and in the worst case, it is discouraging. The best motivation is producing quality work, not getting "good grades".