I am still a F2P player. I usually buy the game with the annual pass at the start of the last season of the year at a discount. I am taking about the Vanguard alerts. At the start screen it says C+, but in most cases I get a B and once a B+. In the Battlegrounds FootHold, we ran through everything so quickly not allowing extra mobs to spawn at Skywatch that I ended up with around 9000 points and didn't get B. So, it looks like a combination of getting 10000 score and finishing fast. But if I had the rewards pass, I would have a B. Every run was less than 10 minutes. There was also a high value target which spawned on some runs, but we did not always manage to capture it. In all cases all players were rank 9 and above and we all knew where to go and how to kill fast. Feels great after slogging through Ultimate. IMO Bungie should have implemented this once they got negative feedback about forcing higher difficulties at the start of EOF.