I have had these three: LBX armatus, Crye JPC 2.0, and Spritus Lv119. I still own the 119, and the JPC 2.0 The jpc is much more comfortable for me, and i run in the carriers about 2-3 nights a week. I only run a little over a mile, but it sucks for me.
I have tried the agilite carriers, and they are pretty comfy as well, although they seem to run big.
The carriers all fit different, and its really probably going to depend on your body type. Im 5'9" (when gravity isnt too strong), about 175lbs athletic build with big chest large traps. I have a few buddies who are taller than me and think the jpc sucks and the spiritus is amazing. They have the lucas botkin gamer body... LOL. Seriously though, If you could try some on that would be ideal.
My favorite setup has been the jpc 2.0, with the haley strategic d3crm chest rig. I usually have a dangler on there as well. Like i said, i switch out my heavier lvl4 plates (ltc26605s) between the carriers when i run, and the jpc is definiely LESS shitty.
The only one in our group that has gone overseas and actually done shit uses a velocity systems, and he loves it. Ive never actually tried it on.