Quiet, moves water, but runs hot
Iwaki's run hot. That being said it is a reliable and quiet pump that works great. As others have said, make sure to run some flexible tubing between your hard lines and sump, and it will cut the noise down a lot. Mine is just a subtle hum in the background. I've had zero issues with it since I got it and would definitely buy again.
Great quality, powerful, low power consumption
If you use this pump you have to use silicone hose or flexible PVC in between the pump in the tank and also the pump and the return. It vibrates which turns into noise. But wow does it pump a lot of water.
Be sure to plane enough room to have 4-5" of flexible PVC between the pump and the sump and the return. My pump puts enough vibration into the sump so it's a little noisier than I like. But WOW does it pump a LOT of water.
compact and quite
I was debating on getting this style pump because they tend to be noisy, so I hear and to my surprise It is way quieter than I expected. Infact I can't hear it over the the other pumps and water movement in my sump.