Spacing tool seems to be a legacy feature for me. It has some display bugs: every time I zoom in, or rotate the viewport, the result disappears from the model. So I have to update the sliders for them to appear again.
Also, It would be nice to come up with a dynamic solution for it, possibly as a modifier or a compound object, so the parameters of the spacing would be available, and the result could be modified later during the design. The same goes for Array function.