We work with engineers, and engineers have many large files to collaborate on. For example, the last engineer we worked with was using a massive FTP file share, and spending tons and tons of time waiting for files to go from the remote server to the users and they finally realized how expensive this kludgy method was for their organization. Using a distributed file system allows them to have the same file on multiple servers and using the FolderMaestro product, they are able to avoid the common file locking issues associated with traditional distributed file systems.
Another firm we worked with we FEDEXing Thumb drives back and forth and killing themselves on cost. Maybe this would work (kind of) for a 2 man operation, but when you have 5 or 10 members of a project team, this methodology is impossible.
Another option is to utilize WAN Optimization as this will speed up the file uploads and downloads tremendously.
For most engineers, we do recommend the distributed file system with a 3rd party file locking program like Folder Maestro.