I guess for me the biggest difference compared to a Charybdis is that it’s a professional product.
I love the Charybdis as a project, but due to the price, I would rather go for something that can resist the test of time.
I also have the Pro version, and I like it, with caveats.
First of all, the LEDs are waaay too bright. I had to change their brightness levels in the firmware, which was not the easiest as IIRC the code for that was not the best documented.
On the flipside, making changes to the firmware, compiling and uploading it to the keyboard is quite easy.
Secondly, the Bluetooth can be a bit buggy. Not only can the keyboard randomly refuse to connect (for which the fix is a button combo to forget the connection), the two halves themselves sometimes have trouble connecting.
Thankfully, that’s a rare occurrence, even if still quite annoying.
The keyboard itself, however, is still quite comfortable for my tiny hands, is very customizable in terms of what key does what, and you can connect it directly to your PC via cable.
The last one also has a caveat, though, as there’s currently no way for the two halves to talk via cable (though I think some people are working on that, at least for the pro version).
I needed something good for work, and I mostly got it. I’m planning to stick with this keyboard until it dies.
Oh, and I like that you can adjust the tenting, though I always use the highest setting.