It would depend on how much you use it, but I would guess a couple of weeks or so. It felt really odd at first, but now it’s very uncomfortable for me to use any other keyboard. A laptop keyboard is pure torture.
Basically, the advantage is that the two halves are approximately perpendicular to your arms, so your wrists aren’t being forced into an unnatural angle as you rest your fingers on the home key row. I am broad shouldered, so using a standard keyboard forces my upper arms against my rib cage, which I don’t like, and I used to get neck pain as a result. That might not matter so much for skinny people.
The wrist rest at the front of the keyboard is also helpful.
You also get a nice open space between your arms for papers, a book, food, or anything else.
There are adjustable keyboards that allow the angle between the two sections to be set to match your individual body geometry, but I’ve never tried any of them.
Very interesting. Thanks for sharing, Fresh Wind.