I bought the original of one of these a few years ago when I lost feeling in some of my fingers. I've since have had a massive reduction in carpal tunnel pain. It took about 3 months for feeling to return to my fingers. It took me a while to get used to the keyboard, specifically the arrow keys and some of the brackets. However, I now type about 20wpm faster than I ever could on a conventional keyboard. I also have a handmade ergodox that I use when traveling, but it's just not as comfortable. It's expensive, but it's cheaper than surgery.