Yes the harness was fairly tight to my body at the beginning of the day, but as the day wore on the front slid up. I have a Fettdad harness that I actually sewed to an old vest carrier that I had laying around. I was hoping the extra fabric would help, but it didn't fix it completely. I have a couple of ideas on how to keep it down. One is to use the larger velcro strap (which is about 4 inches across) on top of the front of the vest carrier. That should hold it better. The MOW pack is just a heavy JP too, so it probably always want to self lower.
The worst part is that it will take another troop to see if helps, since I probably won't suit up and wear it around the house for 5 hours. lol