mine took a really long time to break in.....2-3 months....
mine is also at half way up, and removes about a 1/2" dark green every week.
as for noise i took advice from someone on here i think, and put a wet papertowel over the left side compartment, over the intake, it cut the noise down to silent. 100% better.
the only complaint i have is the amount of airbubbles...definetly dont touch the inside of the cup when cleaning, causes more airbubbles.