This comparison began with a P40 Demo for a graphics design group. The customer wanted to see how the Leica P40 ScanStation would do with St Mary's Cathedral. Needless to say the P40 performed tremendously and got a great scan in only 1hour 30mins with 4 setups on the highest resolution. After doing this demo other customers who owned C10 & P20 ScanStations inquired how theirs compared. So I went back to the Cathedral and replicated the same demo for a simple comparison.