I've been riding the Grail CF 8.0 SL for the past 6 months. Awesome bike. Very comfortable on gravel and paved roads. I actually bought a second wheelset with smooth tyres and I ride with it all the time with my local groups.
In summary, it's agile, fast, fun, and very comfortable. I've ridden close to 1500 miles since I bought it before the summer. Took it on 2 back to back century rides on the road and was really amazed at how comfortable I was throughout the whole ride. I've ridden it over a couple of long gravel rides (50 - 80 miles in one ride). With the proper tire pressure (tubeless is the way to go), the hover bar, and the suspension seat post, the ride over a rough gravel road becomes bearable.
One small regret that I have is the inability for the bike to have an aero bar installed. I'd like to take this bike to dirty kanza next year, and I heard that having an aero bar can provide extra help to combat the challenging headwind. But other people have survived riding in the Kanza without it, so I'll still attempt to ride it next year.
Great bike, in overall. Very happy with my purchase and with Canyon's awesome customer service (I returned my first bike to upgrade to the CF model. The return process was painless and smooth).