I use a touchscreen every once in a while, but when I do need to use it, it's so much better than a touchpad to the point where I won't consider buying a laptop without it (it's one of the reasons I never had a mac btw). Scrolling/reading is a lot more comfortable for longer periods (specially when not on a desk). Also very useful for quickly selecting things (next video/song) without having to move your hand to the touchpad.

I also always buy the "yoga" version, which flips around and has a pen. Very useful when I need to quickly draw something and have no paper around.