Given that it's using the Bittorrent protocol (Basically) to handle the actual transfers, yes it will work; the issue you may run into is that there can be a lot of files and data available in the share and every client will try to download all files.
The challenge here is not data transfer, but interacting with the underlying filesystem well -- handling, say, one user saving a file while another is moving it into a subdirectory, or programs that save files by deleting and rewriting them (or writing a temporary file and then moving it), or similar. That's the real strength of Dropbox.
We're not using that. Dropbox is a shared drive for the company.
My question, still unanswered, remains whether anyone has made btsync work well in a setup where it's used as a shared drive for 10-20 people who interact with many files, though usually not the same file simultaneously (though that happens occasionally, and Dropbox seems to support it...)
