I bought this size on the recommendation of other reviews. We are very pleased with the size and weight. We do not use the battery indicator for when to change the filter as it has no bearing on water use-age but works on how often you remove the top to refill the container (whether you do full or partial refills). We will change the filter every two months on the first day of the even months.
What is great about it is that we now use the filtered water in our Soda Stream and the taste is fantastic. Before we were very disappointed in the taste of the carbonated water with the Soda Stream machine. This was a game changer.