I am using Pix4d Mapper for aerial mapping as background imagery for land surveying and for surface generation for engineering design. I am really happy with the output. I have found the vertical accuracy to be quite good and the horizontal accuracy to be excellent when using GCP. So far, my engineer customers love the product. The learning curve is a little steep but the ability to separate terrain and objects makes surface and contour generation a lot easier. I am still working out what I can do with mosaics.
I have tried using the processing from Maps Made Easy. Although very reasonably priced, the output was not adequate. The image was not good at the shadow line and sometimes there would be two edges. The horizontal control was ok but not consistent thru the image. The vertical accuracy was not acceptable.
I use Map Pilot from Maps made easy for data collection. The output works fine in Mapper.
I am using HP z600 with dual Xeon processors that I got refurbished on Amazon for $600. I put more memory in. Processing times are adequate. Big jobs just get left to run overnite but most jobs take less than one hour.
In general, I really like Pix4d Mapper.