I've been thinking about Blockmarket Desktop versus Blockmarket Web - the desktop version is actually the original concept, a decentralized market that is hosted redundantly by its users. Blockmarket web in theory would be susceptible to shutdowns. However, if enough people are running it, it should be secure. Also, this market does not seem like it's focused on black market and/or illegal items, so there isn't much reason a government would want to shut it down. As long as everybody is paying taxes...
Technically, the Syscoin QT wallet was the original concept of the marketplace, first via console command and then as a GUI directly on Syscoin QT 2.0.
QT, however, is not easy to work with and adding much needed improvements is not only time-consuming but still really ugly and not intuitive or even user-friendly.
This and for a few other obvious reasons, is why we went the web-dev route by first designing an API for developers that harnesses the functions of the blockchain and the using that same API to build Blockmarket as a web-app.
The concept of adding Syscoin masternodes creates a decentralized point-of-entry to Blockmarket web, so yes, one node can be shut down, but not the entire network.
We are not at all focused on black market or illegal items, in fact, we will moderate anything we come across (or is reported) that is illegal in our country (Canada). Although illicit goods are a very large market, in comparison to our target market (everyone else) it is a very small share of the pie.
Yes I've heard QT is a dog to code. There could be vulnerabilities in the web->daemon interface, especially if it relies on RPC, but other than that I think that's a sound development choice.
There are plenty of competitors in the black market space, so the mainstream is a good target. Privacy features are less important and legitimate disintermediated commerce is the goal. One drawback would be lobbying by corporations to criminalize and/or overburden the distributed marketplace business model with regulations, simply to extinguish competition in ecommerce markets. I guess we'll see how this all plays out over the next few years...