I've had the same realization about the iPad after working with webOS on the HP touchpad. I think the reason so much gets taken for granted with the iPad and iPhone is that their design and interface are very intuitive, so that you never have to really spend a lot of energy learning how to do things on them -- what comes naturally usually works. When you use a device that does things differently, you have to stop for a minute and take notice, and actually learn how to do it the way they've designed it (not that that makes it inherently worse).