Wow David, four 3D printers. With experience with four different designs you have to be the go-to guy for printer advice. I'm going to pick your brain to pieces. I've been studying and drooling for a couple years now but have yet to pull the trigger. My first inclination is DIY, but when I add up the cost of parts it seems I may as well buy a kit. Delta printers are fascinating and are the simplest to build, but by the order you listed you arsenal it seems you've moved beyond the Rostock. To me the weak link with the deltas seems to be the bowden extruder. Do you find that to be the case? The FT5 looks good, especially the price. I anxiously await your review.