I used to work sending out those emails for BzzAgent and in charge of doling out points. I can tell you we were told to be sparing with the "Excellent" ratings - in order to receive an excellent the Agent would need to really stand out. Other than that it was up to us which rating we bestowed upon Agents, we were given a formula. I wound up giving quite a few Excellent ratings as long as the reviews were detailed. You would be amazed how many 1 or 2 sentence write ups we would get. The more detailed, and through you are in your review the better that I would rate it. I never was told not to give out so many high ratings, or had a quota to reach. I can only imagine it would be frustrating as everything would be left up to us which would explain how one person may rate you lower and another higher. There's no real set formula unfortunately. That said, it's been a few years since I worked for BA, they may have changed their formula since I left. It was pretty laid back, I really enjoyed working there and do miss it a little.