The results show that an RTK drone platform will give a more accurate position for the center of each image prior to processing, however using RTK has no positive results for the bowl effect which is caused by the lens distortion. Lens distortion still occurs and needs to be corrected by proper image overlap and constraining the model with GCPs.
Is RTK worth the extra dollars? It depends on the deliverable. For mapping large agricultural property, hundreds of acres, where elevations are not critical, 2D Orthomosaic and 2' contour intervals or greater without GCP constraints, I would say yes.
When 3D elevations are critical and 1' contour intervals, GCPs will be needed to correct for the bowl effect due to lens distortion regardless of the drone platform. There is no way around this phenomenon with imagery. LiDAR is a different collection method not analyzed in this case study.
It comes down to the cost/benefit ratio for an RTK drone platform vs the costs for setting the required # of GCPs. The Return on Investment (ROI) is the primary consideration.
My experience has shown that for 3D Survey Mapping to engineering standards, GCPs are required regardless of the drone platform.
The mechanical shutter of the P4P vs the rolling shutter of the M2P has no effect in the accuracy with the sensors of the three drone platforms tested. The rolling shutter bad mojo is an Urban Legend.
As can be seen by the results stated above between the three drone platforms for this case study is that they all performed well when GCPs were applied in the right configuration.
Earlier posts goes into great detail for the right number and location of GCPs.
The cost of each drone platform does vary quite a bit so it comes down to the ROI and what each platform is capable of delivering.