Connect Direct vs. sFTP?

Wikipedia has some nice information at: http://en.wikipedia.org/wiki/NDM.

From what I can ascertain with a bit of searching, it was built to guarantee stability with arguably less of a compromise in speed than similarly flexible solutions.

Having used Connect Direct, I would say avoid it if you can.
My reasons are:

• Is very hard to set up (it took our infrastructure team a year)
• There is a massive learning curve to the application, no one here really understands it still
• We haven't found it any more reliable than psftp and a cron job.

On its plus sides:

• Banks seem to love it
• When it works it guarantees that the file is sent and received and you can be quite sure that the communication is secure.