If you're seriously thinking about buying this go try the other Kinesis keyboards first. After you get in the ergonomic territory I find the comfort increases to be very marginal.
IMHO assuming you have no ergonomic setup at all you're better off buying a Kinesis Freestyle, a used Steelcase/Herman Miller chair, and a VESA mount for your monitor/laptop to make it eye level - all of which can be had for the cost of the Pro version.
That being said this looks like a very nice purchase for those who have the money to micro optimize.