So, in about a month of having beta testers play with the code, we've gotten through around a hundred enhancements, bugs, tweaks and problems (although only a small fraction of these were raised by our beta userswe found the majority with our own testing). There's maybe another fifty that we'd like to get fixed at some point soon, but overall it's looking pretty good.
Predictably, the vast majority of the changes are in the Visual Basic side of things. Partly, this is because the VB code controls the majority of the user interface, and UI code always has a lot of niggly problems. Mostly, this is because the VB code is built on top of Outlook, which is much harder to deal withit's not that well-documented or predictable, and the behaviour can vary wildly between different patch levels of Outlook or even between different configurations of the same version.
The downside of this is that I'm going to have to get far more involved with the VB side of things to even out the load….