When it comes to MF gear transport ... if it ain't got wheels it ain't on the shopping list, or my back and shoulders go on strike.
I know you Mountain Men types need a backpack ... but man-o-man that is a heap 'o weight to be strapping to your back.
Kata has an interesting take on the dual need ... it has slip over sleeves and uses their Interfit dolly wheels for full transport.
I use one of their big system bags for the Hassey along with a smaller shoulder bag with waist harness that also slips over the dolly handle. The smaller bag is international airline sized and can use the same dolly by itself, then be slid off the dolly for shooting transport, or stowing on a smaller airplane. That bag carries a H3D-II with 100/2.2 mounted, a 150mm, 50mm, 28mm (or 35mm), 1.7X extender, 13mm tube, 5 grip batteries, charger, CF wallet, and Metz flash with spare batteries.
Lots of nice bags to select from these days.