From my own experience lifesize voice and video quality is so awful that anything from an egineering company should be superior. Also the stability of the lifesize appliance is horrible. Often enough we've to reboot them before every meeting, because the microphone went dead again. The only positive point is that it works with Chromium on Linux including the window sharing extension. I hope it's of slightly better quality then webex. But I fear that is overly optimistic at least.

On the other hand Google Hangouts is for free, has from my experience a better quality and all of them ship your data to the US. If amazon offers something similar they and can offer an option that keeps your data in Europe that would be an interesting option.