been doing progress documentation for a mid-size contractor for about 8 months now, mostly using DroneDeploy because the client wanted something their project managers could just log into and see without needing to learn anything. works fine for that honestly, the annotation tools are good enough and the timelapse comparison thing is genuinely useful for them.

but ive been running into accuracy issues on the edges of the site where theres a lot of elevation change, like a 4-5 meter retaining wall situation, and the orthomosaic just goes really wobbly there. thinking maybe Pix4D would handle it better with more control over the point cloud processing but i dont really know if thats actually the issue or if its my flight plan.

anyone switched between the two for this kind of work? or is this more of a GCP placement problem than a software problem

almost certainly a GCP problem. if your ground control points are all on flat areas and youre expecting the software to extrapolate correctly up a retaining wall youre gonna have a bad time regardless of what you're processing in. Pix4D does give you more knobs to turn but it wont fix bad input data.

that said i do prefer Pix4D for anything with complex vertical surfaces, the rayCloud editor lets you manually adjust tie points which has saved me a few times on awkward geometry. DroneDeploy is just way more of a black box. great for clients who need a dashboard, not great when something goes wrong and you need to understand why.

we had almost the exact same situation on a quarry project last year. the warping along the faces was embarrassing until we added checkpoints specifically around the vertical transitions and redid the processing. also ended up doing a second oblique pass at like 65-70 degrees to get more coverage on the wall face itself, nadir only wasnt cutting it for that kind of relief. not sure if youre already doing that but it made a big difference for us