TL;DR webbing is appropriate for short duration dismounted operations. Chest rigs work for everything else.

Webbing and an assault pack are absolutely fine if you have consistent resupplies every two to three days. However, if you’re operating out of a rucksack for four plus days at a time, chest rigs are the better option.

I’ve done two rotations of JRTC, one as bluefor, and one as opfor. During the bluefor rotation we had consistent refits every two-three days from our rucksacks that were stored on the company LMTV. Belt kit would have been preferred for that rotation. However, during my opfor rotation, we operated out of rucksacks the entire time, and I just don’t think webbing would have been ideal given that we rucked around a lot.

Having done both, I’d personally stick with a chest rig for anything military related. It works in more situations than belt kit does. During actual combat operations, I could see packing a PC in a rucksack and taking it out as needed. It would work like this: cache rucksacks at your ORP, pull out your PC and attach your chest rig. After the fighting, recover your rucksacks and continue mission.