I have been looking for a good programmer keyboard for a while now and quickly tested the Microsoft Sculpt keyboard. The Sculpt is a promising mix of good quality and reasonable price. At around $80-90 it is at the higher end of split "natural" keyboards but considerably cheaper than a lot of ergonomic keyboards.
The Sculpt uses low-profile "chicklet" keys similar to most laptops. The keys are actually very good and comparable to Apple keyboards and the Chromebook Pixel. I quite like the keys on this keyboard, nearly as much as the Pixel's (my laptop of choice for development).
What really drew me to the Sculpt is that it is narrow having no numeric keypad, which I never use. (It comes with a standalone numeric keypad if you want it.) Plus the arrow keys and home/end/page keys are merged into the main bank of keys, again saving width.
The big advantage to "narrow" is that the mouse is usually right of the keyboard and if one's arm has to move too far past the shoulder it can cause pain or discomfort. I hadn't noticed any particularly pain, but the keyboard tray on my desk isn't wide enough for a normal-width keyboard to be centered and still fit a mouse. So I had to have it off-center because I often use it as a stand-up desk (rest of desk doesn't raise). After using the narrower keyboard I won't go back, it is much more comfortable even if I could have the normal keyboard centered.
Getting used to the Sculpt was mostly easy as it is a fairly normal layout, though I did run into two issues:
One, it turns out I don't touch-type quite like I was taught. I tend to type 'Y' and 'H' and '6' with my left hand instead of my right, I don't know if it's because I'm left handed or a programmer (type lots of semicolons, curly braces, enter, compared to normal text) or just have bad habits. This is a problem on a split keyboard. After a week this wasn't too bad, except when my right hand was on the mouse.
The second issue is worse: note the location of the arrow keys. This is the same spot which I love on the Pixel's keyboard and do not like at all here. The difference is the Pixel has dead space above the keys but the Sculpt does not which makes it much harder to feel the position.
Related to this the Pixel uses a modifier where the caps lock would normally be to turn the arrow keys into home/end/page up and down. I find this very convenient but on the Sculpt these keys are in a stack on the right side which I also couldn't feel.
For these two reasons I decided the Sculpt is not clearly "the one" but good enough to keep as a contender.