It will also be much, much cheaper to use than eBay. I can't wait that they finish it though.
It might be cheaper and even better, but without the numbers or userbase it wont be much good. It's how I look at bitcoin. Obviously its better than fiat but it just doesn't have the userbase or merchant adoption yet.
Without some huge media campaign I think it will take a while to build up a sizeable OB userbase (especially to people outside the btc community), it took Ebay years to get established so I expect OpenBazaar will also face the same challenge.