They also don't have butyl sidewall reinforcement the way a dh tire does.They definitely feel burlier than the specialized SX tires. I think they weigh less than 'normal' dh tires because they're kind of small and they don't have a wire bead.
A schwalbe super gravity has the full dh sidewall, but thin xc single ply under the knobs. The michelin has full 2ply thickness, but without sidewall reinforcement. It's like a continental baron tire, just with a Kevlar bead instead of a steel bead.
They are for sure less sidewall than a schwalbe or maxxis dh tire. Weather that matters to you is something else.