My office uses Updox much like David's. A few comments:
1. I believe that you can "port" your own fax telephone number to Updox (with their help) in most cases, which means you can save money by giving up a fax line.
2. The faxes from PT/OT, home health and the like, which need signature and fax back, can be all marked up, signed and refaxed without paper.
3. As David implied, there is a general "practice" workspace and individual user workspaces. You can reassign an incoming document to a specific user to review and act on.
4. The patient portal can be used to post electronic forms for patients to complete, such as registration, history updates, etc, which can be received in Updox and imported into AC.
5. The Updox method of importing documents into AC is superior to AC's own method IMHO. The document can be named, sorted into a category, responded to with a comment, sent to a staff member or patient with a message, and faxed out as part of a collection of records, all with a single click.
6. All this costs me $45 a month, for 3 registered users and 1,000 in/out faxes.