I got a K1C a few months back and am buying but delighted with it. I came from a gen 1 Ender 3 with a warped bed. The only complaints that I've had are that the spool relocation included should include relocation of the runout sensor and the nozzle cleaner should not be part of the build plate (fixable with an easy mod).
Closed source firmware on a 3d printer is just a non-starter for me. Even if the printer were 10x or 100x better, I'm not dropping that kind of dough on something that will leave me screwed if the manufacturer decides to enshitify or goes bankrupt.