I have yet to get a cogent explanation of how this project is any better than hosting a mamp instance on your home computer, running an ecommerce package. Seemingly, the authors believe that their system will bring free sales in your door, because it 'doesn't need' google to index your site. :/

Hey Chris. I know you like your own ecommerce project a lot better; that's understandable.

Have you actually used OpenBazaar yet?

Give it a try yourself.

Have you ever personally set up and run a self-hosted website, then installed an ecommerce package, then installed plugins to accept Bitcoin?

I think you'll find OpenBazaar a lot easier to install and use. Plus some other neat stuff like a market for escrow agents.

I have. In Fact, I wrote my own ecommerce market from scratch back before I realized that "but with the bitcoin apps" are mostly wastes of time: https://github.com/brighton36/CoinPost

I read some of the slides, focusing on the sybil attack mitigation. Just how hard is this PoW? Is it really hard relative to the potential gain from fraud?

Given that the potential is infinite, no. But it is certainly a useful point at which to have a scaling factor in place.

My main thought: This thing needs support for privacy-enabled cryptocurrencies.

It's on their road map.