WARNING: DO NOT click the Subscribe All button unless you fully intend to download ALL maps on the workshop. There is an "Unsubscribe from all" button now if you accidentally subscribe to everything, however, this will unsubscribe from everything on the workshop, including maps you want to keep.

Thanks, Steam; I can no longer add new items to this collection: http://i.imgur.com/wZ6NAuF.png
Thanks again Steam, now the collection appears empty. I've split it into two parts, Redux and Redux.5:
Redux: https://steamhost.cn/steamcommunity_com/sharedfiles/filedetails/?id=2928129714
Redux.5: https://steamhost.cn/steamcommunity_com/sharedfiles/filedetails/?id=2928181870
Part 2: https://steamhost.cn/steamcommunity_com/sharedfiles/filedetails/?id=880346817
Part 3: https://steamhost.cn/steamcommunity_com/sharedfiles/filedetails/?id=1686918408
Part 4: https://steamhost.cn/steamcommunity_com/sharedfiles/filedetails/?id=2257451298
Part 5: https://steamhost.cn/steamcommunity_com/sharedfiles/filedetails/?id=2840748734

All workshop content, for use in solo arcade or for hosting multiplayer.

You DO NOT need this collection anymore to play online multiplayer. As of build 3466, automatic downloading of workshop tracks was added.