I own both an EZ and a Model01, both have their advantages and disadvantages. I’ll offer my - slightly biased - opinion after the pros/cons list.
- Has more keys (76 vs 64)
- MX keyswitches: better keycap compatibility, and more variety to choose from
- Recent EZ models have hotswappable switches
- QMK is more mature than Kaleidoscope (the default firmware of the EZ and the Model01, respectively)
- The EZ has a smaller bootloader, meaning you can fit about 2k more on it.
- The thumb cluster is… not that good. With my average hands, I can comfortably reach three keys out of the six
- The pinky column is horrible if your pinky is shorter than average (mine are)
- The tenting solution on the EZ is nice, but caps around 15 degrees. More than traditional keyboards, but 15 degrees ain’t much.
- The thumb arc is comfortable, all four keys are easily reachable
- The pinky column is positioned noticably lower than on the EZ, which makes it a lot easier to use it with shorter pinkies
- The tenting solution is super-flexible, just see the custom mounts thread on this very forum
- Per-key RGB LEDs (the EZ only has an underglow)
- Open source bootloader (in case you care about that - I do)
- Custom sculpted keycaps guide your fingers much better than anything else on the market today
- Palm keys
- Only two switch variants: Quiet and Loud, much less than the switch variety available for the EZ (mind you, Matias Quiet Clicks are <3)
- Custom sculpted keycaps means you can’t buy a custom set of caps; if you need replacements, or a different set, the only vendor is keyboard.io
- The Kaleidoscope firmware is less mature than QMK (but see below about firmware)
If you want to buy custom keycaps, go with the EZ, or anything with MX-style switches. If you are not happy with Matias switches, go with the EZ. If you want per-key RGB LEDs, better thumb keys (and a palm key!), a superior, incredibly flexible tenting solution, go with the Model01.
When I was looking for an ergonomic keyboard, my finalists were the Model01 and the EZ, and I chose the Model01 (but still got an EZ, because I needed something sooner, too :P). I chose it, because I wanted to use a very high degree tenting (currently sitting at around 40-45 degrees), I liked the idea of custom sculpted keycaps (I don’t want to buy any custom set, the few keyboard.io provides perfectly cover my needs and desires: a blank, a translucent and a linear A set is all I’ll ever need), and the wood frame hit home hard, too.
I love both the EZ, and the Model01, both are very solid pieces of equipment. But I found the Model01 to be a better fit for my needs. It had more ergonomic thought behind it, so to say. I loved it when I first saw it, but now that I’ve been using it for a good while now, I love it even more. The lowered pinky column was a surprise, which I didn’t even notice at first. But when I found that I’m using my pinky, I was delighted (on the EZ, I only use my pinky for the home row; the rows above or below, I press with my ring finger after a bit of hand movement or gymnastics).
In the end, you can’t make a terribly bad choice, as both devices are great. I find the Model01 more convenient to use, but unlike a lot of mechanical keyboard enthusiasts, I don’t care about custom keycap sets, and the Matias Quiet Click switches are the closest to what I imagine the perfect switches are.
The EZ ships with QMK as its default firmware, which is a battle-tested, mature firmware. The Model01’s Kaleidoscope has seen much less testing, and isn’t as solid as QMK - yet (but we’re constantly working on that). Kaleidoscope does have an advantage in that it’s - I hope - more user-friendly. When working on the firmware, one of the primary driving forces is ease of use for the novice user. To make it easy to get started with.
I think we’re quite good on that front, we have a number of third party plugins already.