You might want to consider this pad, or the Torso-only version of it. The air baffles run left-to-right, rather than head-to-toe, so the pad stays flatter. You can deflate the pad and leave it in the sleeve when the bmbh is packed up. This pad is insulated.
Haven't tried the Big Agnes pad mentioned above...so cannot comment on that one.
"Climb the mountains and get their good tidings.
Nature's peace will flow into you as sunshine flows into trees.
The winds will blow their own freshness into you, and the storms their energy,
while cares will drop away from you like the leaves of Autumn."
— John Muir