I think the one you're missing that is most important is the current state of battery technology. Notice how the indoor version of BigDog has a tether for powe

I think the one you're missing that is most important is the current state of battery technology. Notice how the indoor version of BigDog has a tether for power and the outdoor has a very loud engine. That noise hardly acceptable on the battlefield. Are these considered "robots"? http://en.wikipedia.org/wiki/Close-in_weapon_system http://en.wikipedia.org/wiki/Close-in_weapon_system http://en.wikipedia.org/wiki/Northrop_Grumman_X-47B http://en.wikipedia.org/wiki/Northrop_Grumman_X-47B