What fish are you cycling with? Also, I am curious - are the glass holes overflows relatively silent?
I have a pair of designer clown fish in one of the tanks. I also just added a small starry blenny to another, he's awesome.
I would not say they are nearly silent. My previous tank had a bean animal setup, that was nearly silent. The glass holes are not loud but I do hear them. I do think it's a nice product for these smaller tanks.