I've never run gravel-kings (RH tires are special runs from Panaracer), so I cannot compare to them, but the Endurance + version now on both slick and treaded versions of their 55mm 700C tires. Both are superb. My kid, who races XC in non-pandemic times, has taken over the treaded ones
(Fleecer Ridge) for his XC bike, and likes them better in many respects when compared to true mountain bike tires. (As a bonus, the price tag of a fleecer ridge is in-line with what people pay for good mountain bike tires, so you don't feel like you are getting fleeced so much.) He set them up tubeless with their Panaracer sealant. They were fiddly to seat, he said. The XC bike has rather narrow carbon rims.