Using this on a gravel bike but would hesitate to use on a road bike either. The ergonomics of the hoods and pivot point of the brake lever is superior to the road Di2 equivalents.
GRX ST-RX815 Di2, eye-catching for a gravel bike upgrade, These are great fit in the hand. Shimano put a little off-road feel into these shifters, allows me to hold tight as the hoods are sleek; I feel I have a good firm grasp on the bike, and it wont get away from me on a bumpy decent, tested on Forest park. The electric shifting is a real bike up-grade, making the shifting experience quick and efficient.
As I enjoy both a cable system bike and this electrical shifting system. Shimano is a reliable, well build system.
Di2 is not necessary nor for everyone; the gears shift like a 'mouse click', and I did it with my pinky (laughs).
It doesn't make cycling easier, you just go faster (shifting gears)