I find average mechanical keyboards to be perfect for my typing style. They never cause me hand strain, stress, tension, etc. Membrane keyboards, however - and especially whatever you call the keyboards on Macbooks - feel like I'm trying to finger drum on glass. I end up with tons of hand pain.

However -- the qualifying fact is that I am a pianist, from the age of 5. I believe that a lot of the biomechanics I learned at the piano keyboard transfer to the computer keyboard, whether I want them to or not. I can't help but try to type the way I play piano to some degree -- in large part, this means an elevated wrist, a pretty high finger force and more of a hammer-type finger action rather than a pressing-type acting.

A very important part of any instrument training is learning correct technique, and a large reason for this is the prevention of injury. I've had decades to adopt the correct technique for keeping my wrists elevated and my fingers hanging down without tension. And I'm sure the increased finger strength helps, too.