Collaborative nature for distributed teams; ability to store and share latest versions of files; organizational abilities of system; ability to "hide" private docs; ability for clients to e-sign.
I have found very little elements to dislike about the paperless product or customer service!
I would highly recommend Paperless Proposal. It's easy to use, provides for organization, collaboration, storing and sharing of files, videos in proposals, ability to upload documents, and electronic signing by clients.
Business problems being solved are disorganized distributed teams. We have seen efficiency among teams and in time to market with proposals. It saves us time and money in terms of staff time and helps us get information to clients when the clients are looking for it.