Did a mock walk PT test tonight..
I can honestly say for me the walk was EXTREMELY easy. Not once did I feel out of breath, nor did I really have any pain in my legs. If I had the option of doing the walk or run I would pick the walk every single time.
I am not a Super Soldier running 13 minute two miles, I probably average a 1430 or so and I'm usually pretty good with the other two events.