I would never trust Box. A long time ago (probably when they were starting up) the service made me realize that you can upload whatever you want for free but when it comes to download, you'll be SOL.
As someone else also mentioned it in the thread, my experience was that you could upload folders/files but when it comes to download back, I could not download the folders. I gave up the moment I saw that limitation.
Dropbox doesn't have such restrictions, nor do any other such service I have experienced in the free tier.
Box allows you to download any files or folders. It's better than Dropbox in one respect because it automatically keeps a certain number of versions of a file (up to 25 I think) so you can easily backdate to a legacy copy in case of emergency.
