I've got one on my Rio 240. I bought it earlier this year and it was very noisy. APS were ok to start with and sent a new impeller but when that didn't solve the problem they started giving me the runaround.
I suspected the head unit but they told me it was trapped air or kinked pipes etc. Eventually they sent a replacement head unit after I threatened to return the whole lot and now all is good.
It's quiet, it's powerful and it's cheap, shame about the customer service though.