Champion Mastery
I've been flying through the ranks of Champion Mastery, and because of the low max it does not feel important. As an experienced player I'd get laughed at if I walked into a plat game and was like man I'm so cool I have the highest tier champion mastery, it took me a whole 30 games to get it! I've played 200 games on my main just this season, another 1300 on him(Ezreal) since S1. 30 games is trivial to me, and you look like a noob to be proud of a meer 30 games.
Not trying to be high and mighty, but rather give Riot feed back. It does feel really good to progress in the mastery ranks, I wish it could be something that has real meaning. On a side note Riot, I main "AP" Ezreal mid, and you gave me the ADC title -_-