I don't have an MS split keyboard on every computer I use, and there are technical reasons why I couldn't even if I wanted to. While it is true that I could learn to use two kinds of keyboard, it is stressful to have to think of which keyboard I am using. The last thing I want is to be losing efficiency and comfort with ordinary keyboards - but it seems that that is the result of becoming comfortable with the split keyboard design. This is no reflection on Microsoft, or any other designer of improved keyboards. If I decide that the benefits of these split keyboards are worth it, and especially if I can find some with good keys and a standard key layout, which I can connect to all my computers, then I might consider using them.
Links Here are some links of interest.
I am not trying to develop the definitive link-farm in these fields. Diagrams and explanation of carpal tunnel syndrome. This is supposedly the home of the Typing Injury FAQ, but when I tried, the server did not exist. Keyboards, software and other resources for one-handed people. Looks expensive, but excellent.