I've used the UHK daily for a bit over a year now. Planned on writing a full review (which I feel the product deserves), but I'll mention some notes here.

I initially purchased the keyboard to address wrist pains. Likely from my years of development and gaming. Looked at many available split keyboard options. Tested a coworker's Keyboardio which was very comfortable, but pretty bulky and had a high learning curve for its non-standard layout. This was only a problem when I needed to switch back to typing on a laptop. That doesn't happen often but it did slow me down. Felt the same way about the Ergodox. Very comfortable, but took a while to get used (and then a while more to switch back to standard laptop) and it wasn't easy to cart around. Although, a benefit I found from the Ergodox was the fully programmability. This includes mouse programming. While it doesn't compare to having a pointer device, having mouse keys programmed allowed me to use the mouse without moving my hands away from the keyboard. I try to use keyboard shortcuts as much as possible, but today's design is very mouse/pointer heavy. With some site operations being mouse-only. Having that functionality (while not perfect) is great for me.

The main features I ended up looking for came out of testing those two boards:
- Split keyboard
- Close to standard layout
- Portability
- Mouse functionality

The two boards I found that fit these were the UHK and the Kinesis RGB Edge that other commenters have mentioned. While I couldn't test the UHK, I did get to try the Edge out at PAX last year. I really like it. It's not the same comfort as the Keyboardio and the Ergodox. But your fingers already know where to go without trying or having to learn anything knew. Keymapping worked really well. The macro keys were nice, though I didn't have time to play with them. It's somewhere in the line of 80% of a full standard keyboard. Which is enough for most. It did however lack in the portability department and didn't have a mouse layer. Not deal breakers, but lacked everything I was looking for. I'd like to try the Redox(w) at some point. At the time though, I ended up taking the leap and purchasing the UHK. It took over a month to arrive. Here's a list of what I like about it:

- Can be used split or combined into a single board. I've found few split boards can do this. Helps with portability.
- Tilting works well and is very stable. Though it requires tools to change the tilting.
- Build quality is great. There is a nice (steel?) frame that the switches are mounted to. This quality extends to the wrist rests which have a nice metal plate to attach them to the base of the board.
- Each key I need to press is within reach of my fingers. The Ergodox and Edge had some keys which were out of reach for me.
- The mapping software is superb! I really appreciate the design and some additional features from that. The very first thing I changed was setting `/~ to Esc. In my mind, this should be the default for any keyboard with the word 'hacking' in the title.
- While they seemed gimmicky at first, the 'mouse' buttons on the bottom frame of the board are easy to reach and use. Since they are a unique features to this board, I use them to active that mouse layer which works very well.
- The small profiles allows it to fit really well in a small audio equipment case which I found at a music shop. Again, something difficult to do with the larger, awkwardly shaped boards.
- Most importantly to me, my wrist pain has reduced dramatically.

In regards to the wrist pain, I will say that my case seems to be more related to wrist movement than wrist angle. The keyboard helps with both. If I had a way to reduce wrist movement with a standard board (not needing a mouse), I likely would have been fine continuing to use one. While the pros have resulted in a board that I'm happy with, I feel I should also list some cons:

- The switches (MX Clears in my case) feel extremely dry and gritty. This isn't the case with my other keyboards with Clears. I've tried lubricating them but they still have a bit of grit.
- The standard keycaps are not great. While it's clear the board has a lot of work put into it, the keycaps seem to be an area ignored or sacrificed for cost resulting in thinner (ABS?) plastic. This would be okay but some keys are not standard size so it is difficult to find higher quality replacements. I bought mine with blank caps and a spare set for when these get worn and glossy. If I had one request it would be a replacement set of keycaps from UHK in a higher quality plastic.
- Every once in a while (maybe once a month) a layer gets stuck. I'll activate the FN layer by holding down a key and releasing that key doesn't deactivate it like it should. By that time I've already tried to type something else only for it to respond with weird behavior I didn't expect because FN is still active. I then have to press the FN key again to deactivate.
- The LED read-out only works for the built in mod-layers (i.e. QWR for QWERTY, DVK for Dovorak). I use multiple profiles and it would have been nice to be able to program that LED for each profile. Or at the very least, use it for something fun.
- The seal on the wooden rest has started to wear a bit. I'll likely sand it down and refinish it if gets worse.

Ultimately, I'm super happy with the UHK. The Kinesis Edge would have been an easier option. However, it doesn't have all the features I was looking for and I prefer not to just buy whatever is available on Amazon. If you have a standard board and want to try split, I would recommend the Edge. The UHK is more expensive and takes time to ship, but I feel it's worth it. Especially if you're looking for something a bit more solidly built, more portable, or you need a mouse layers and other customizable programming.