Microsoft has a terrible history of launching stores or services and then shutting them down. I have no confidence in anything bought directly from MS still being accessible 1-2 years from now. At this point, Steam is stable, easy to use, well-established, and carries the vast majority of games that interest me. There is no reason to use anything else. I make one exception for Origin because my wife really likes The Sims, so I have to keep Origin installed for that, but I wish I didn't have to. I wish EA would sell on Steam too. I find the Origin interface irritating to navigate and search for things, particularly expansions, which show up in some places but not others. If Origin has a shopping cart feature, it's so well hidden I've never seen it. It looks like you have to purchase every item you want individually. Maybe there is a cart somewhere (because I can't believe they wouldn't have one), but it's never appeared for me.