We use Dropbox for Business. I don't think it's the Advanced Tier. I do not feel there is much value added beyond the regular Dropbox, but I don't know how limited regular Dropbox has become.
I have often discussed the "ecosystems" we use in our business to my staff. I am "with" Google Drive and Dropbox and Quickbooks Online and Rent Manager Online (version iX) etc.
The point is, I use Google Drive with my managers as a "shell" -- i.e. Hello new manager after the old one went bad, you need to be able to run gmail and get to "your" Google Drive and print files & forms there etc. I can upload a PDF to there and you can grab it whenever you need it.
I do not use Dropbox with my managers. I use Dropbox for my back-end files within my management office. On-site they have paper files that they take to court, if necessary. We have fax-scan-PDF of the "files" in Dropbox.