Check some reviews for the Seachem Tidal 110, a worthy competitor to the AC 110, but with some design advantages, including quality, flexible plastic, better flow control, and a submerged pump, meaning none of the restart/priming issues the AC is sometimes known for. On the other hand the AC rates at 500 gals per hour vs 450 for the Seachem. The AC looks bigger sitting on a tank, but the Seachem is deeper (taller), so not much actual difference in media volume. I don't run them now but I've had both, and both are good filters ime. The Seachem wins for me due to the priming and better flow control, but, like anything, I'm sure there are varying preferences between the two.