I used to run two MP10s in my 75, but I switched to the 120 and now run two RW-8s. The quality definitely isn't there, but I could literally buy 4 of these RW8 pumps for the price of one MP10. I would have upgraded to two MP40s, but at almost $400 a pop, it's a little hard to justify. The RWs work very well and have a few nice settings, but obviously not as many functions and 'nifty' features as the MP line.
You get what you pay for, but if you understand that, the bottom line is they both do what they are designed to do. Move water.