Yes, your computer does have to be on for Plex. Not a big deal for us since ours is always on, but I know it does bug some people. The biggest benefit is that our family can all watch a show together, where we aren't likely to crowd around the computer monitor to do that. I have found that we watch more TV as a family now that we dumped cable. It doesn't seem like it would be that way, but it is, at least for us. I don't miss cable at all and my wallet doesn't miss it either.