Like many of you, I'm waiting to see more of these upgrade kits out in the wild. I love the idea of dual extruding on my UM2+, but if it requires a priming/wipe tower to do every dual print, I can't say I'm happy with that. I've seen a CTC Bizer Dual Extruder machine at work, and there was no requirement for any kind of tower. Granted, that was on the dual extrusion hazard cone model, so perhaps it didn't require it.
Anyway, would love to see some more samples of this in action and even a detailed video walkthrough of installation.
I'll be patiently waiting.