my fax number is not portable, and there is no local number even for me to forward my current fax number to.
Why isn't your fax number portable? Updox has an option for porting it. In any case, you can get an 800 number through Updox that should be a free fax for anyone in the US or Canada.
What is the big advantage of using Updox like this as opposed to Paperport alone?
I have only been using Updox for about 3 weeks, but I agree with Martin's observation that it brings together all the components of receiving and sending documents by fax, email & scans, importing into AC, posting on a patient portal, electronically marking up documents including signatures, etc. There is no equipment investment except your present computer and internet connection, and no software upfront cost, it's pay as you go.
Since Updox is a Java program, I can sign on anywhere I have an internet connection (including on my Mac at home) and review documents, mark them up and re-fax or email them out. However, you must be at a computer running AC to import documents into AC.
I have also found their tech support the equal or better than AC, both email, chat and even telephone support, including extended hours -- even when I was doing the free trial.
The Updox web page reminds me of AC's website -- minimal information and tutorials on how the program works. I suggest doing the 15 day free trial to see if it meets your practice's needs.