You're in the right forum for your topic.  "Chat About It" is always a good place for any topic that doesn't obviously belong to one of the other DNN project or topic categories.
 
Regarding document management modules:
DMX 5 is a very nice documents management module but it may not operate just as you expect.  (A few notes on that, below.)

What are your requirements? 

• How many documents? 
• Will you need to limit access based on user roles? 
• How many "document managers" and how often will such managers change (i.e., will you have temporary managers or constantly-rotating managers)?
• What is the technical "comfort level" of your document managers?  Will they be able to deal with DNN wizard interfaces or do they need something simpler?
• Will you need to link to documents not stored within your DNN site's PORTALS subdirectory?  Put another way: Will you need to include documents that you can NOT upload to your web server?
• Do you need document revisioning?
• Do you need approval for document uploads / changes? (workflow)

There are many items to consider.  Generally the larger your organization the more requirements you'll find that you have.
 

DMX 5
Document Exchange from Bring2Mind has been around for several years.  It's a solid module and one of the few that currently support webdav.  One of the big selling points for many customers is the ability to enable drag-and-drop from Windows Explorer into DMX's Explorer-like UI.  This makes DMX a hit with the less-technically-inclined end user.  DMX also presents files via templates which allow you to present lists of documents in various formats.  For instance, you can present files via a Windows Explorer-like UI on one page, in a simple expandable tree on a second page and as a simple Documents-module list on a third page.  You can include more than one instance of DMX on a page -but- you cannot present two "Windows Explorer" interfaces on the same page (you can but some controls for the second instance get routed to the first instance).  There is usually no problem when combining other templates (non-Windows Explorer) together on the same page.

Another limitation is mass-import of files.  While you may certainly import many files at once, you cannot import a directory structure.  This means that all imported files will be placed together in a single directory.  You'll need to manually recreate any desired file directories.
 
DMX institutes its own "fileID" solution (much like DNN fileIDs).  Files are appended with ".resource" and can ONLY be accessed using special DMX links.  Your DNN instacnce (ASP.Net, actually) will refuse to serve up the file from a direct URL link due to the ".resource" extension.  If you have a requirement to link files using direct links then DMX is not the module for you.
 
Overall I think DMX 5 is a great module -- lots of features, dependable and good performance.  There are certainly some areas that need improvement (the multiple "Windows Explorer" instance clashing I cited earlier, for instance) but I've not run into anything that wasn't workable.  The page on Snowcovered includes a link to a working demo (but only limited admin functionality) as well as a free trial download.
 
 
Good luck with your module hunt-
-mamlin