I know it's been a few months since the last post but I thought I'd put my 2 bits in.
In searching for other stuff on Craigs list I ran across a lady who had several tanks. When asked, she said the Rena 400 was the quietest one she'd ever own and swore by it.
So off I went looking for it, got one, a new one, on eBay for $32.50 shipped, great. But in doing so I found many that had broken plastic outlet nipples which are not easily replaced as it and the inner parts are of a single solid piece (not user changeable).
So, if you get one, I'd suggest attaching the two short airline tubes that were included to each of the two outlets then use a straight in-line adapter to connect it to the airline running into the tank.
That way if and when you need to disconnect/connect you can just hold the short airline tube and the tank line to pull disconnect/connect thereby taking the force/pressure off the nipple itself.
20 gallon long est. Oct '09 Folsom, CA.
Flora: 10% Duckweed, Amazon Swords, Java Fern, Java Moss, Anacharis & Anubias.
Fauna: 18 Cardinals, 8 Pygmy Corys, 6 male Endlers, 3 Otos, & 3 Ghost Shrimp
Filter: AquaClear 50 with foam, fiber, & 2 biomax bags