Our dev time is coming to a close, we've put a code freeze on as Alex compiles and packages the project for submission. I feel that we've achieved a fair bit given 5 man days - we were even able to use the product as a tool for sharing the project plan around from about half way through!
It's been a great learning experience for two new technologies. From the DFS side, I think we're all quite familiar with the new architecture and on the whole see a number a benefits. One downside we all agree on is that, on the whole the construction of DataObject structures is very 'heavy' and requires many more lines of code than the DFC equivalent. There is a lot of scope for writing a number of wrappers and convenience tools for reducing the amount of code needed for new DFS functionality. Similarly, being coarse-grained provides flexibility but again means some code is less readable and less convenient than before.
I'm sure with a bit of time to develope your own layer on to of the DFS client libraries, DFS will become a great way of developing web or thick client apps using whichever app technology you desire.