I have not tried the workshop module in a course I test it and always arrive at workflow issues for both the instructors and the students. However, I am most excited about this module over any of the others really. Just because it needs some work doesn't mean it shouldn't be commended. Rome wasn't built in a day.
I am launching a course next week where, for the first time, I will be using the workshop format a lot. However, I chose to run them in forums as opposed to the workshop module. I can't wait to see how workshop can be put to use though once some of the workflow challenges are solved...the biggest thing to get your head around is how the time frames of everything work online. That must be very challenging as a developer.