I think the noise idea was the question at hand. I know many people own different pumps and seem to belong to the club of "I really like the one I own" it is comforting to think that you purchased the best one.
But
Any high pressure pump is a high velocity pump and is a lot louder than a low pressure pump.
If you talk to the tech rep. at sequence he will tell of the Reef series that are low speed pumps and are quiet and do not give off a lot of heat. Then there is the high vol. high pressure pumps that are not good under a tank, because of volume.
A dart does give off a good flow if you do not add a ton of fittings between the tank and pump, each 90 degree adds a foot of head, and ball valves, unions etc., you can really restrict the flow. Also 2" in and 1.5" out.
All this said, you will like the pressure of Iwaki etc pumps better but I will guarantee you will not like the noise as much.
One other example, I have a hammerhead on my return from my sump. A single 1.5 inch feeding, if I run it at full speed there is only one word for the entire 400 gal reef tank "Jacuzzi"