The new Roubaix’s numbers take around 30mm of stack out, add 10mm to the reach and have shortened the head-tube to 190mm. The wheelbase is over 10mm shorter thanks to shorter chainstays, so the new bike has more in common with the pro-racing Tarmac than anything else in Specialized’s range.
I have a tarmac and just picked up a 2015 Roubaix, because it was too "racey" for me and my old age. Now they are making it more like a tarmac? Glad I got my old Roubaix when I did I would never bother with the new one.