The reason you want a touchscreen on a laptop isn't so that you can use it for "an extended period of time" but rather so that you can use it to do the few things that are painful with a touchpad, like drag and drop.
There’s been plenty of times where I would rather drag an item on the screen than fiddle with the sometimes flaky responsiveness and range of a touchpad. I’m usually fussy about my Asus laptop’s pad - the MacBook _usually_ does fine in the touchpad area. The best was my old ThinkPad’s nipple - preferable in most ways to what I use touchpads for at all.