Girder is a great product, but until recently, was focused on windows/media automation (interfacting IR equipment, etc.), which it did really well. Since 4.0, they started focusing on home automation as well, which is probably why not too many people are using it yet for that purpose.
They are pretty comitted to the home automation aspect from what I can tell, since they are working on an Elk driver, Insteon driver, and more. The only shortcoming imo, is the steep learning curve, but this is something they are working on as well. Combine Girder with their NetRemote (the touch screen software), and you have a winner.
I see from your nHome post that you have quite a few home automation software packages... Girder, Homeseer, HAL 2000, etc. Are you just using Girder now or do you really use them all? Don't they somewhat provide 75%ish of the same functionality?