I've been running one for a month. It's very quiet, easy to maintain, and works well.
On the negative side, it's a little sensitive to water level, doesn't surface skim, and I've noticed a small amount of micro bubbles in my tank.
Overall, compared to other nano skimmers that I've read about, I would still pick the Tunze. My main concerns were getting a skimmer that worked, was quiet, and wouldn't overflow onto my carpet. The Tunze meets all of those requirements easily.
