I've been using mine, via Kickstarter, for a while now. Frankly, I love it, despite a lot of drawbacks.
I've used old MS Natural Ergo keyboards for, well, at least a decade. The old beige PS2 ones. But they're getting harder to find in good shape. So I tried an Ergodox. Really nice idea, and I adapted to the linear letter columns fairly quickly. What I couldn't do was retrain myself regarding all the other keys. I gave it months and could never get the hang of them. That's a problem I foresee for me with most fancy split ergo keyboards, they insist on having the halves mirrored, which eliminates all those keys my decades old muscle memory wants over to the right.
The X-Bows splits [heh] the difference. It's got the letters aligned in columns and turned out a bit, while maintaining the keys on the right in pretty much the same locations. While I never got back to full speed on an Ergodox, I was up to full speed in a couple days with the X-Bows. But, remember, that's coming from an old MS ergo keyboard, so the letter positions were only minimally changed for me.
There are hefty drawbacks. As other have noted, the letter areas aren't as turned out as they could be for anyone with broader shoulders, which a true split keyboard would allow for. Nor is the keyboard tented at all. Doing either of those would have kept this from ever being produced in the first place. It was all they could do to get these out the door as is and folks who ordered the magnetically attached number pads are still waiting for them.
There's no config software for Linux and Mac folks. I doubt it's coming, as the X-Bows team has admitted they lack the ability. That said, I was already used to a keyboard set in generic PC keyboard mode with my Mac, so I'm not feeling the loss of Mac-specific functionality. My wife is using an X-Bows, too, but is sorely missing correctly mapped function keys. There are neither Home nor End keys. I don't use them anyway, so I don't miss them. If you do, though, you will.
The Alt key is ridiculously huge, but if you use a Mac, it's a huge Command key and that's just awesome. It's right under the X and C keys, making it the easiest Command key I've ever used.
So, functionally, I love this keyboard, but that love is highly dependent on my particular experience and use cases.
The keycaps are an issue. I'm not in love with the feel of them. If you disregard the extra keys in the middle, all the keys are essentially 1U or 2U keys and can be replaced with normal rectangular keycaps in those sizes. I'm currently using a "vomit layout" using the results of some PMP grab bags. Photo is attached. It looks simply hideous, but feels really nice. Getting a nice-looking layout would take some doing. I don't think most keycap sets come with 1U shift, tab, and backslash keys. Maybe some Planck sets would work?