Gentlemen,
Good points, all.
In my opinion, we have no choice but to retain convoys for resupply in theater, and that is mainly due to the dearth of road options. When we were running resupply to the PRT (Camp Nathan Smith) from KAF, one of the first things we did was try to open up additional routes so that we had the option of varying our movement.
Unfortunately, logistic vehicles tend to be large and heavy, and cart paths through wadis tend not to be able to support them.
What we eventually decided upon in order to minimize our vulnerability was to vary times (always), take advantage of hours of darkness, only run heavy convoys on routes that supported heavy convoys (all light convoys used the wadis etc), carefully consider packet size and composition (force protection vs unwieldiness) and minimize the amount of material that was carried via military tpt. If it could be delivered via jingle truck, it was.
This turned out to be relatively effective in my opinion. We generally got everything through in a timely manner, and reduced the risk to our personnel as much as possible.
To minimize risk further, of course, we treated all personnel as fighters. I am extremely proud of our CSS troops' performance. While they would not be my first choice to go assault an MG position on a hill, they displayed excellent abilities in terms of protecting their convoys and maintaining vigilance.
CDS drops are good, but they will never fully replace resupply on the ground. For time sensitive material, or materials that do not justify the resources of an aerial mission (cargo lift, gunships, mission planning time/pers, loss of ability to react elsewhere) convoys are the way to go.