I see you're investing loads of time and effort into producing an ULTRA smooth flying heavy lifting rig rather than focusing solely on a rig that can lift a heavy load. Faster spinning smaller diameter props will certainly produce a smoother flying rig, it's finding the perfect prop size/motor kv/lipo voltage combo that makes it grueling. It's also exciting to hear that there are so many prop size options for a big lift rig running 6s with the kw10s...13"-15" props can be used depending on payload. I'd never guess that 13" props would be enough to lift a rig hauling a full Epic setup. As for your previous setup, it takes a brave soul to build an octo with 830kv motors on 6s! Sounds terrifying!!!