I have a Dewalt DS708 12” compound sliding miter saw that I bought new years ago.  The saw’s slide bars are positioned one over the other.  Not long after I bought it Dewalt came out with the DWS709 which is essentially the same saw except that the slide bars are positioned next to one another horizontally.    I assume they (and other manufacturers) made the change to side by side sliders because there is an advantage over sliders positioned vertically.    I’m not about to sell my DS708 but  I’ve always wondered what that advantage is.  Accuracy? Repeatability?  Because everyone else made them that way?   Just curious.
George