Yes, there are many documented advantages.
Copied from here and then adapted:
...the adjustable keyboard was more comfortable...in comparison with the conventional keyboard.
—Tittiranonda, Rempel, et al. (1999) “Workplace use of an adjustable keyboard: adjustment preferences and effect on wrist posture”
...split keyboards place the wrist closer to a ...
Plausible reflex rates for limited functions. But won't replace keyboard and mouse.
A real answer could only come if someone tests the product in a laboratory and writes a solid review. But here's my educated guess:
Many non-invasive brain-computer interfacing (BCI) systems are based on measuring P300 signals with EEG, which take about 200-600ms. So ...
It seems that using computers in general does not cause carpal tunnel syndrome, regardless of the type of keyboard. Some references:
"Carpal Tunnel Syndrome: The Epidemic That Never Was", Canada's Occupational Health and Safety magazine, September 2001
"Computer use deleted as carpal tunnel syndrome cause", Harvard University Gazette, February 2006
An alternative theory that is not yet listed here is that the origin of the QWERTY keyboard layout was influenced mainly by telegraph operators receiving Morse code and transcribing it using early typewriters. The layout was based on their feedback and suggestions.
According to Cognitive Consequences of Programming: Augmentations to Basic Instruction Journal of Educational Computing Research , volume 2, pages 75-93 (1986):
Teachers we surveyed recommended that we help students become better typists. Lack of typing ability was perceived as one of the largest obstacles to success in programming.
So at least at a ...