Rigs are often compared to Lego systems, since they can be assembled according to your imagination. It's hard to justify the cost of industry standard 15mm rigs if all you need it for is to stabilize your camera. You can already do this with a few broomsticks and duct tape.
It starts to make more sense once you start to involve mounting audio accessories, lighting accessories, monitors, evf solutions, follow focuses, and matte boxes. Especially since some of those items require rails to mount. Clamps and rods also make it easy to redesign and customize size and shape depending on the individual. You can grow with a starter set of rails, or you can shrink down from a large rig. Not to mention the benefits to traveling. A large set of rods and clamps can be packed up pretty nicely. Lastly, there are many who just want the pure aesthetics of it.
Here's a closer look at the inline version of the 'EVENT' DSLR rig from Express35. There is so many good things about this rig, but overall you'll find the price is the best part. Express35 stabilizers are made in the USA, and it's quality rivals many of the top local DSLR Stabilizer brands, and yet pricing competes with the cheapest of over seas rigs.
This particular EVENT rig is designed for EVF or LCD Monitor use by keeping the camera in line over the shoulder. You can also use this setup with cameras that have Flip out LCD screens. The contoured shoulder pad wraps behind the shoulder (doesn't sit on top), and the counterweight that sits low balances the rig out even more. With the dual rods on the counterweight, you can offset this if you feel you need to shift it over more to one side. I prefer to have the weight adjusted to sit lower. You can also just shoot without the counterweight, and still have plenty points of contact for stabilizing your camera.
Normally you'll see adjustable handles with some rigs, but those could have a tendency to reposition (slip) under weight. The Express35 XL HD handle is one solid piece which really adds to the whole stability of the rig. The 13" length and 4" offset design of the front handle makes it extremely comfortable to operate with less strain in your arm. There's a few optional pieces I suggest to really get this rig going. The optional top handle makes it easier for me to lift the rig on/off my shoulder or to hold the rig in a position for low shots. The optional tripod mount obviously makes it easier for you to get into tripod mode for some fluid panning (or just docking the rig). The 90 degree accessory rod clamp with stub makes it easy to attach or detach a 1/4-20 accessory. In this case i'm using a friction arm with Zacuto EVF with the rod clamp.
The only other item I'm looking to add is a second handle. It's not necessary to have a second handle for stabilization when shooting video on this rig, but the second handle will allow me to place the rig on the floor without falling over. If you decide to look into Express35 gear, make sure you put in a good word about this Cheesycam blog. To find out the exact pieces that come with the EVENT, and optional accessories, check out Express35.com.