Biggest improvement, from my point of view, is the addition of a toe tab and removable heal tab compared to the R1 model. A very comfortable & lightweight shoe. My only addition would be for reflectivity on back of the heal.
Delivery was fast, race shoes are amazing. Already put at least 400 Miles on them and they have held up extremely well. Took a little bit to get used to the stiffness, but in the end love them.