Here’s my current setup. The rig itself was made by Coyote Tactical, while the pouches are a mix of Paraclete, CT, and Recce Gear.
I run my Camelbak tube under my left arm. The hydration pouch has side ports, and the tube is routed with grim locks and Velcro/elastic. My radio ends up under my left arm and my dump pouch (folded up in the picture) hangs under it on some long malice clips. On my right side is a modified Chuckwalla, which holds my BB loaders, spare batteries, and glasses.
It consists of four parts: the front, the two sides, and the rear hydration carrier.
The front flips up, and the inside is lined with Velcro to keep the sides in place. This makes it very easy to put on and take off. It would also be very easy to switch between two different front pieces (say one with M4 pouches, and another with AK pouches).
The rig also has a small bib. It’s big enough to hold two M4 mags side by side (an AK mag is shown in the picture). I use it for maps, power bars, and other small flat items.