I had a great flight with me Klima Auriga that I modified as a two-stager with a cluster o' four motors on each stage. This flight was flown with 4 x D9-5 in t' booster and 4 x D3-P in t' sustainer. T' on-board camera added weight and a lot o' drag. Well, blow me down! This made t' D3 motors struggle t' accelerate t' sustainer. Avast, me proud beauty! For this setup D9 motors in t' sustainer would be a better choice.