I had a great flight with my Klima Auriga that I modified as a two-stager with a cluster of four motors on each stage. This flight was flown with 4 x D9-5 in the booster and 4 x D3-P in the sustainer. The on-board camera added weight and a lot of drag. This made the D3 motors struggle to accelerate the sustainer. For this setup D9 motors in the sustainer would be a better choice.