I run this tire as a front tire on my Aspero Gravel Bike. I initially bought the 40 mm as most of the riding I do has a good deal of asphalt. The G-one R is has just enough bite on most gravel to keep control and also maintain efficient rolling on asphalt. As a front tire the ware is very acceptable. I am not sure I would run as a rear tire but I imagine it rolls equally well and but likely faster ware. This tire will work well for category 1-3 trails. On looser terrain, some care is needed and lower air pressure. Once my 40 wares out, I already have a 45 to replace it.. I feel its a great tire for most of my needed. If more of my routes had looser terrain I would lean more towards the G-one X or consider something else.
I have run the 45, 50, and both color sidewalls of this tire over the past year. It has proven to be very durable, fast rolling, and hooks up well in the rough stuff. The transparent sidewall seems to weep more than the black wall until the sealant sets up. No problems after the initial setup when it comes to holding air. Measures as stated on 25mm internal hookless rims. Other tire favorites of mine are the Tufo Gravel Swampero (love it, just want to run larger than 44) and the Mezcal, (same, want to run larger than 44). This has been a great choice for a 45-50 aggressive gravel tire.
Put these on my Ritchey Outback 650b style for a trip to Florida to help with the occasional sandy gravel. Brought my 29" "more-roadworthy" gravel wheels with me to swap out and never needed them. Put ~200 miles on the tires during the trip and found I could keep up with roadies on N/S rides along the gulf (and into the wind). These things are fast. I've yet to test them on chunky gravel but on hardpack and pavement, they rip. I'm all Schwalbe these days across 12 bikes unless there's a unique situation (20" mini velo or 26" resto mod) where they don't make the exact tire type I'd like.
