Smart micro is great... I use one my my 125g system and and one on my standard 10g. I also have a duetto on a sumped 20L. It's much like the smart micro, but a few dollars cheaper. Pro for the duetto is no light in the water level sensor so it doesn't act like a moon light if you don't have a sump. It also has a low level and high level in one sensor (low level will kick the ato pump on, high level kills the power if the pump were to fail and continue to pump). Overall I think the build quality of the smart micro is a tad better, but they are both good little ATO units.