Should you pay the extra for touch Chromebooks?
The simple answer is YES.
Chromebooks with touch and stylus capability is what your next investment should be. Having the touch functionality allows you to plan lessons that are rich, hands on and extends learning. Here's an example below.
Post test assessment in mathematics, students used Google Keep and Screencastify to draw and identify 2D shapes. They identified features of a shape and explained their thinking (from varying mathematical abilities). This was used as a post assessment to 2D shapes.