I can speak from experience with the Ergodox EZ version of the ergodox. I should have done more research before purchasing it. I've experienced a stubborn debounce problem that's been mentioned by other users in forums and QMK issues over several years. I experienced it with the original firmware, and also with QMK, which I tried out of desperation. Switch bounce effects are somehow unaffected by turning debounce up to 250ms. It's not my only ergodox, but it's the only one with this problem. I've come to the opinion that there's something structurally wrong with the EZ's design.
I momentarily considered the Moonlander as a replacement until realizing that both the Ergodox EZ and the Moonlander are made and sold by ZSA.
Debounce can be very personal - exactly how you push the keys has a significant impact on bouncy/chatter your keys are. It's not just about the mechanisms.
I have an ErgoDox EZ as my daily driver, and have occasionally had some debounce / chatter problems, but they've never been that serious for me. I bottom out hard on every keystroke, which is not ideal but I've never been able to retrain myself away from it, and I think that's part of why I have the issue.
Bumping the debounce up a bit worked for me. YMMV.
There's a version and batch number on the bottom of the keyboard, mine's batch 3a and V3. From what I've gathered it's hit or miss. This EZ is the only keyboard I've had issues with. The interesting part is that it's specific keys. Iffy solder joints were my first guess but that checks out. I haven't put the effort into checking components yet.
I like that the thumb cluster on the Moonlander has an adjustable angle - the fixed angle on the Ergodox EZ wasn't the most comfortable fit for me. As well, if you are going to be carrying the keyboard around with you, the Moonlander folds down flat and comes stock with a neoprene carrying case and the hex wrench to readjust it, so it's fairly trivial.
I've also had no debounce issues across two of them.
Yes if you have to buy only one, Moonlander is the right choice. If one has access to a 3d printer, they have a community set of cad files for useful accessories (e.g. more tenting support, if needed) [0].
