For riding on mainly country roads with a bit of track/bridal path type activity, I've settled on some Schwalbe s-one tyres, running tubeless, and I am certainly discovering the qualities of the bike and am enjoying riding it - I did 100km yesterday on very varied terrain, road, gravelly / muddy tracks, the south downs way.
The 30mm S-ones were not quite big enough for some of the terrain, but I remained upright all day, just about! (probably due to the fact that the ground was still fairly firm in most places due to the cold) It was certainly fun though. And this is the first time I've had disc brakes, thru-axles and tubeless tyres - all of which are brilliant and making me re-consider what to do with my other bikes!
I'll be having some more adventures and probably will invest in some 650 wheels and bigger tyres for fully off road trips, as I personally think that's where the bike's strengths lie...
...I'm starting to see how it can introduce me to new 2 wheeled fun in a variety of ways, which I guess is one of the main points of the bike!