Without a doubt, the UHK (Ultimate Hacking Keyboard). It changed (for the better) the way I use my desktop. I even ended up buying a travel case for it so I can take it on business trips where I will do a lot of keyboarding. By far my favorite home office purchase.
I have tried a lot of split keyboards. Haven't tried the Glove80, but I have used the Kinesis (Advantage and 360) and other scooped keyboards. They feel very naturally ergonomic. Allowing your fingers to move in a way that feels more comfortable to your hand. The split design furthers that by putting your hands at the distance they should be separated. The pros: very comfortable resting position, minimal hand, wrist, and finger travel. The cons: Size and dedicating yourself to a unique layout. The Kinesis (even the 360) takes up a lot of space. The bigger issue for me though was that I had to retrain my brain for standard layouts every time I sat at a computer with a normal keyboard. Imagine building the most comfortable bike in the world, but then not being able to ride in other cities because 'your' bike is at home.
Long story, I found the UHK to be the best option. While it doesn't have the scooped or natural key placement, the layout being standard staggered allows for existing muscle memory with all the benefits of the split and tilted design. I now have two UHKs for home and office. And I would buy another if they weren't so easy to travel with.
I have not, but looking at those it seems they are missing one of the killer features: a mouse layer. Being able to control the mouse quickly and efficiently with the keyboard is a killer feature and one I couldn't part with.
