I was looking for a bargain chest rig for a fibua package a couple of years ago and stumbled across a brand new NL on ebay for silly money. For carrying ammo, grenades and water it worked a treat. There are two ammo pouches each holding 4 mags, with built-in grenade pouches on the front. The big utility pouches worked ok for water bottles but trying to get much else in there (and manage the contents properly) was a bit of a bitch. Would fit a minimi mag superbly I reckon though.
Nice and compact too. Guys with COP vests and normal webbing had to take their kit off to get through mouseholes etc but I managed to keep mine on all the while.
There are two zipper pockets which could house maps/orders but not much else (def not a 9mm) and four smaller pouches around the side/back. The smaller ones are ideal FFD/gps etc pouches but the medium sized ones look like ammo pouches - but can't fit mags and are too narrow for anything thicker than a compass. There's loads of strapping to look after too.
They probably edge over a normal chest rig for vehicle or even fibua work, but cannot match normal webbing for when you've got your ass is the grass or sustained exercises/ops where you need to carry food and section kit.