Arc mouse is 14.22 mm thick and weighs 82 g, and uses AAA batteries, and is a two button mouse that lacks a scroll function.

This thing is 4.5 mm thick over most of its surface, with a 10 mm bump where the sensor lives. It has a scroll pad and weighs 40 g. These things are in different universes in terms of size and thickness.

You can say, "the Arc Mouse is only three times as thick and twice as heavy, but it also changes shape, and I see no reason for a better solution." you can say that, but thinking the arc mouse does the same thing as this device is hard to square with the basic dimensions of each mouse in question.