I’m happy with the ergodox-ez. I haven’t tried my hand (heh) at any other ergo mechanical keyboards so I have nothing to compare it with.
The fast prototype printing is a very important feature that I’m happy to hear you’ve been successful with. I’m surprised that you’re printing your own keycaps but I suppose it’s the only way to get the specific shape.
Do you have other ergonomic keyboards? If so, do they use custom caps as well?