Recommendations for integrated Document Management System alternative to NetDocuments

Hi we currently use NetDocuments as our integrated with Salesforce DMS.  While we are largely happy with the software, we are looking into whether there may be a better alternative out there.

A couple of the frustrations we do have with NetDocuments are:

1) the inability to clone detailed folder structures when setting up a new workspace, and

2) our clients have access through a "client portal" to a limited number of the folders within our NetDocuments structure and some have told us that as people who don't regularly use the system, they do not find it particularly user-friendly.

I'd be very grateful for any DMS recommendations, or equally, warnings of software/companies to stay away from!  I am particularly curious to hear about Box.com, Egnite and SpringCM.

Thank you very much!