I've not read this entire thread, but wanted to chime in. I ride Force 22. I'm no engineer, but it seems to me that having one lever for brakes and one lever for shifting is fundamentally less complex and therefore more reliable than the way Shimano does it with the dual function brake lever. Just my two cents.

Also, there is a youtube video reviewing Ultegra vs. Force. The reviewer is a bike mechanic and he says the shifting on the Force was less "finicky" than on the Ultegra. That swayed me quite a bit.