Re: aikido vs jiu-jitsu
I realize that Aikido is about the last MA that I would recommend for the military unless you became trainees at about age 12 and didn't see combat until age 18. It simply takes too long to learn. The majority of the MAs hailed as the most effective can be taught to large numbers of people and have them proficient, not expert, within a year's time. Muai Thai, BJJ, Wing Chun, and Western Boxing are the first ones that come to mind. Aikido does have a place in the world, but it seems that the place it has is directly related to your mindset and how you were taught.
Here's some food for thought: during his last years O'Sensei would sadly say "I've given my life to opeining the path of Aikido but when I look back no one is following me." An American student said to him once "I really want to do your Aikido." To which he replied "How unusual! Everyone else wants to do their own Aikido."