Critique your boss with extreme care!
A colleague in my team was recently made redundant due to so called "structural changes". The announcement came as a total shock to all of us since she was shouldering a ton of the boring administrative work that no-one else wanted to do, and she was fairly good at managing it all. Our team is actually growing (5+ new hires in the last 6 months out of ~22 globally) so downsizing isn't really an excuse. I was actually lost for ideas as to why they would let a productive, valued team member go. Then I thought back to a couple of weeks ago, the formal peer review process. We both were recently placed under the care of a new manager who is not entirely popular in our team, a political worm who manages to gain credit from higher places without doing any actual work. I remember my colleague telling me she was not happy with the way he was managing and sought to voice her disgruntled opinions to the big boss through a supposedly anonymous peer review. So it turns out this worm is the MD's favourite son so to speak. What do you know, three weeks later she is fucking axed like Ned Stark.
Moral of the story, be very careful with this formal peer review process. Everyone likes to say it's the one time of the year you are safe to put everything on the table, get out all your opinions and frustrations about your colleagues and bosses. NO. Be aware of these political allegiances even in small teams. The first agenda of power is self-preservation.