I don't know anything about Desura. They doesn't seem to offer more than Humble, do they?
I've got a personal thing which is “always buy a game, download a software, purchase an album, order a movie, acquire a book from the official website, or — if no way to get the piece of work is directly offered on the website — from the main store directly linked from the official website”. That's often how you are sure to get the latest version, get all the updates, all the extra content, all the platforms available, and where the more money will go to the creators.