Kinesis can strain your thumbs. I used one for 14 years. Still got major wrist pain and really bad thumb pain. Microsoft Sculpt Mobile and that style of keyboard ended up being my best option.
Recently the pain came back worse than ever, this time accompanied with quite serious thumb pains, I certainly do not blame the Kinesis as it is most surely a combination of many factors (poor habits, stress, workload, etc.), but the layout does increase the load on the thumbs so I think that contributed.
For now I have switched back to a cheap Microsoft dome keyboard as it is easier to type with using only my forefinger and middle finger (and easily allows me to avoid using thumbs and pinkies).
Of course this is all just my personal experience, for years the Kinesis was lovely and I may still go back to it, as always YMMV.