Ok, thanks. I have both computers using the same "library" on the share so, only update once.
That is true, quite a few modifications I think. You're very dependent on writing all tags to the media files or to sidecar files for video. I have never studied this, but I do think there are some file types and some tags that are not possible to share between windows SMB share only. You need a Library server for this to be reliable. To update all your tag changes and be certain it's replicated to all other clients.
I also believe that you're very dependent on Automatic import being enabled everywhere. Without it I think you'll have trouble checking for this external changes from other clients.
So, overall I would say that a true JRiver Library Server is the way to go. Not only a common share. But in your case you might do without it for the clients. I think it depends a lot on what media you have, and if my first assumption of file types and tag problems is true
One other thing. For the phones, you'll HAVE to have a library server. A client computer can run this, but if it does, I do not see much of a point in not hoocking up the other clients to it...