Nothing prevents me from using a source port after purchasing the assets from GOG (in fact, the source port installer is designed to use GOG assets if available

Nothing prevents me from using a source port after purchasing the assets from GOG (in fact, the source port installer is designed to use GOG assets if available.) The thing that prevents some people from using source ports is that they don't know they exist. I regularly run into people who have bought Descent from GOG or Steam and are upset that they can't get multiplayer working, who have no idea about the source ports. (I normally find people like this in the chat room or forums for the prequel, Descent:Underground -- http://descendentstudios.com/ http://descendentstudios.com/ . It's been less than 24 hours since I last helped someone who had complained about, in this case, the Steam version, which is nearly identical to the GOG version.)