Too much sediment, poor filter construction, inconsistent operation, questionable water temp.
Had this brewer for just over 2 months and returned it for a refund. The sediment problem was too much, even after experimenting using coarser grinds. The filter is a bit flimsy and gets loose over time requiring repeated tightening. Because the filter is plastic, the threads don‘t hold up to being tensioned repeatedly and the heat from the brewer affects this problem too.
The plastic lid/cover that goes on top of the unit is so tight that you‘ll think you‘re going to break it getting it off the first time. It is very difficult to work with until you‘ve snapped/unsnapped it enough times to wear it out a bit. I didn‘t like that design and just left my lid in a loose state to avoid fighting with it. This is a known issue to Starbucks and they say it is designed that way for safety (legal CYA really).
I noticed (what others have seen) that the amount of time that the water spends "north" was noticeably inconsistent from day to day. Much of the water is drawn up into the grounds well before it has reached optimal brewing temperature. Using a digital thermometer, the highest temp I could record when all the water was "north", was about 180F. In my opinion, Starbucks is marketing a very interesting/alluring brewer that doesn‘t seem to measure up to the standards of other Vac brewers that have stood the test of time.
Cleaning requires a bit more time/effort than a drip brewer and is messier (especially if you choose, as I did, not to dump grounds down your drain). You cannot get your hand through the opening on the carafe and will have to use a narrow brush or sponge. Cleaning the upper part (the funnel) requires going around the bowl and wiping out the grounds by hand.
I really wanted to enjoy this product, but it just isn‘t ready for "prime time". One last thing, I felt that the flavor was rich, but that I had lost being able to distinguish some of the more subtle flavor differences between my (home roasted) beans that I was able to taste with a good drip brewer.