Unless your prices are going to be a lot cheaper, CP already sells this one...
I've used mine for about 9-10 months now, but only brought it out for the real important shoots. For someone my age (JC student), donning on such a vest would only raise eyebrows. Yes, you might look dorky, but at least you look dorky in the most comfortable way. I wouldn't want to imagine the state of my shoulders after shooting a wedding on my relatively heavier gear without one of these.
Never used their pro-camera inserts though. My 1D2n performs well without them, for now.