My ErgodoxEZ:

- nearly made me cry.

- solved my back pain.

When you didn't learn to type properly, relearning to type can be a very difficult task; re-learning on a split keyboard is particularly unforgiving. Around three weeks into re-learning I was convinced I would never learn properly and that I'd wasted a lot of time and money (I was freelancing at the time) on something that wouldn't help me eat, never mind sleep.

Two weeks later I was back up to normal typing speeds, a month after that I was faster than ever. Two months or so after that, my back pain was gone.

Of course, my back pain was caused by sitting lopsided - something an overdominant hand on a standard keyboard pushes you towards. No amount of exercise and posture correction was solving it - but when the true cause was resolved it cleared up (with exercise) very quickly.

I'd buy this keyboard again in a heartbeat.

I actually found going from non-split to split surprising easy, simply because none of my old muscle memory worked anymore, and I had never touch typed up until then, so I wasn't able to go back to the old way out of frustration. A few hours of doing touch typing drills on some free online thing, and I could type at 30wpm, and then it only took about a week of doing my usual coding, IRC chatting etc to get back up to my usual 100wpm.

Also surprising was that after I got there, I could also touch type pretty easily on a normal keyboard. But my old ad hoc 5 finger typing had somehow disappeared entirely.

Countervailing story: the Ergodox (EZ specifically but that's less important) gave me permanent RSI in my thumbs, because it was too big for my hands, and to this day I pretty much can't use a keyboard layout that relies on lots of thumb involvement. Even just hitting the spacebar throughout the day or using my thumbs to type on a smartphone is enough to flare it up, almost a decade after I stopped using that keyboard.

YMMV, ergonomics are highly personal with respect to your body size and proportions. We didn't have the proliferation of keyboard layouts then that we do now. Perhaps if the Iris or Corne had existed then, I would still be using my thumbs for modifier keys in a 40% layout. I never got the hang of tapdance or hold modifiers.

The Atreus layout is the only one I can still use somewhat, because the thumbs are held closer to the hand rather than splayed out.