2 completely different pumps, the big benefit of the mp40 is the electrical part is outside the tank, so the footprint inside the tank is minimal, and comes with lots of pre-programmed modes, and customer support is second to none, also the wireless link between units is awesome. the wp40 is completely submersible in the tank, has a big footprint, doesn't have the ability to link to additional wp's , not as many modes of operation, but moves alot of water similar to the vortech. I use both in my tank, only time will tell about the reliability of the wp40's . As far as cost goes the wp40 is a no brainer. Hth