Make that VERY heavy. Like most, it is designed for those who use the LCD screen. It is not user friendly for those that might want to look into the viewfinder. Quite the bargain, though.

how's the built? metal or plastic feel? Will the bracket moves along with your breathing?

Holy cripes that thing would have to be heavy! Whatever amount of weight that hangs in front of your shoulder blade would have to be equally added to the back. My shoulder is starting to ache just thinking about it.

If you're worried about arm fatigue, the DV MultiRig and other products are much lighter and transfer the weight of the camcorder to your hip. The plus side is that the MultiRig folds into a tight package. Admittedly, the belt and assembly require a few minutes, and the downside is that low altitude shots are limited by the height of the suspension. This is an issue for us in indoor mixed martial arts in which the action goes to the floor. For that reason, I switched to the VSB-1. I can see your draw to a $65 brace, but I now prefer the flexibility of the Vortex Media VSB-1 .
http://www.vortexmedia.com/EX1DVD/VSB1.html

You can add whatever counter weight you like, including useful counterweight such as a field recorder, accessory batteries, etc.

It is metal. It is rock solid. But, it is very heavy. That's why it works so well.
If you are going handheld all day, look elsewhere. Otherwise it is fine.

And what about eye strain trying to look at an LCD just inches from your eyes for long periods.

The only shoulder support that I have found (other than Zacuto) that is designed for those of us who want to use the viewfinder is Chrosziel's DV Balancer. I have tried the DV Caddie, the Steady Stick, the Stasis, the CB105 and (my second favorite) the Varizoom VZ-LSP. None can compare to the DV Balancer. It is light as a feather. It takes a while to adjust to your body. Like being fitted for a suit. It works as advertised. The downside is that it is ten times the price of the CB105. After a couple of months of using it, I still love it.
I bought mine from Chris at ZGC.

$655 for THAT???

Chroziel Matte Box on EX-3
 

Here is a photo of the PCI custom tripod plate for EX-3 camera. A gel shoulder pad (not shown) makes it possible to use the camera on the shoulder.
http://www.dvinfo.net/conf/members/p...eivers-etc.jpg