So far I am very impressed with Clinked. It is easy to set u up clients and brand them individually. My primary use is as a virtual document room but I can see a strong use case for project work either with in-house teams or freelancers. I really like the fact that I can set different levels of access for different files by using a combination of the file/directory permissions and subgroups. Clinked also has an audit trail so I can see who accessed what files and version control - all essential for secure document sharing.
The one thing I didn't like as much was the experience of guests. Instead of single use links (one email link = one file/directory share), I think it would be better if there was a page or mini portal portal that showed all files a guest has access to when they click the emailed link.
Another thing I would love to see id a LTD buy-up for some of the Premium features (watermark, more storage, etc). Maybe after the Appsumo deal?