our gravel roads are maintained regularly, and that means that deep gravel is pretty common. I went from 30mm tires and 20 flats a year to tubeless 38mm tires and zero flats, and everything about them is a lot better. Much more secure on long, curvy downhills. I'm not even sure there is a measurable increase in rolling resistance. We have some roads that the forest service calls "jeep trails" and my tires can go faster than my willingness to bounce my brain around on that stuff.