I use 2 x Eheim compact 5000's (5000 l/h). Their power is great for their size, their price was great for the power, so is the little dial to choose how much you want them to pump but they are very noisy for such a small pump and considering the hype Eheim gear gets about how quiet they are. Eheim dropped the ball on this one. I managed to dull them with "cages" I made by siliconing some extra foam I had together to try and dampen the noise. The sump is also surrounded by polystyrene on the three sides it touches the stand (bottom, back & side) to try and aid in noise reduction.
I would swap them out in a heart beat for New-Jet pumps if I was able, like the adjustable 3000 l/h one I use for my water changes. Very quiet, even used outside the water in a plastix tub (to keep it off the carpet while it is running).