Just to add a fifth point: Lifespan. I'm typing this on a Majestouch that I've owned for more than 10 years. I've had to replace the keycaps twice now due to wear, but the keyboard still works perfectly and feels as new.

It's certainly the oldest piece of technology in my office. I've typed on newer fancier keyboards (and have a 60% for travel), but the Majestouch is still my favourite.