The coppers are, I think, linear switches with a very low activation distance (vis-a-vis reds etc). I do not feel that to be necessary for typing, and they might actually be a liability for negligent triggering just from resting the fingers on the keys.
I have another hot swap keyboard ergo keyboard and purchased both Kailh red and navy box switches. I started with the navy (a heavier version of the clicky whites you can also choose with Atreus) then had to share a space with somebody else and swapped to the red, and can’t be bothered to swap back. I don’t really feel the need for tactile or audible feedback but many users do. I find the reds are lovely and soft, whereas the navies required a bit more of a ‘whack’.
Many who are new to mechanical keyboards go for brown (tactile) as a good interim choice - a little feedback so your fingers can learn where the activation point lies without being noisy or too ‘chunky’ in feel.
Edit: I am glad some of the options are starting to run out as it provides the opportunity to reappraise the switch options for future batches. I would like the “Quiet box” switches added to the options in subsequent batches. Should Keyboardio be willing retool then a thinner more portable Atreus designed around Cherry Low Profile switches might be even more desirable…