P4Pro is a great solution. Just got it. We are a mapping company and I have flown them all, been doing this for 7 yrs. The enclosed quality report shows the results we have been seeing on average. This particular flight was at 45 meters altitude, avg. ground speed of 9m/s, flying a 65% frontlap, 60% sidelap, getting 1.3cm accuracy. Photos taken in 4:3 aspect ratio, but should achieve better sidelap at 3:2 ratio (tomorrows flight). Flight planning done in DD, flown with ios and processed thru Pix4d. We are happy with getting to a <1cm accuracy level.