Pretty solid rig overall loaded with 270 rounds of 556, a quart of Gatorade and 2 MREs in the buttpack doesn't feel too cumbersome. Tried magpul and stanag metal mags without trouble. As advertised you will need either range plates or magazine extensions to grab everything with any expediency. Likely won't run 40 rounders, but a +5/6 extension will probably work fine with how much room is left in the top.
Also fits two 25 round 308 pmags without trouble and three 8 shot shell cards from pewpewkoncepts with plenty of room for the pull tabs
The chest strap does have a lot of extra strap for different body types though for me it might be a hair too much.
Bekt adjustments are pretty similar to a bianchi or safariland duty belt but is easier to work with since it doesn't have the duty belt stiffener sewn in. Belt pad is nice qnd cozy as well. Distributes weight a bit wider on the hips.
Shoulder pouch is the perfect size for a 4 inch oles bandage with the suction cup for better seal though I do wish it was just a hair bigger to put in a full blow out kit or an issued ifak. Works for what it's intended.
Flare pouches are also the perfect size for extended pistol magazine pouches. I recommend running the elastic to keep retention on it however because the pouch itself isn't the most secure method
At current. Butt pack is holding 2 fully packed MREs though definitely seems like there's enough room for a rain layer and a lot more miscellaneous equipment that you can stuff and…