I will just add that the strikes I learned seemed to be effective IF I would initiate them, basically by surprise. If I was squaring off against an opponent who was ready for a fight, the success rate of these techniques would be severely diminished (as Kevin noted). Which reinforces my desire to seek out a system that does not foster this type of aggressive tendencies, hence my interest in Aikido.
I'm not going to lie and say my motivation to study this is purely for the aesthetic of it. Gaining some knowledge and insight into how people carry themselves that can help get me out of a potential confrontation is another plus.
Surprise is very, very key to success. It is also the thing I think in most self defense situtations that is capitaized on by the attacker.
I could possess all the years of training in martial arts, in a toe to toe fight and in a classroom I may be much more competent than they other guys, however, I think you can throw that all out the window the minute he jumps you by surprise, dictates the rules/tempo of the fight, and has maybe a weapon that he is employing like club, knife etc.
It also goes out the window if he brings a buddy and I don't.
So, I don't think there is much we can really do ultimately given this element (surprise etc.)
However, I still think there are things we can do and train properly to improve our odds or survival if you can survvive.
It all comes down to structure...learning how to adopt a defensive structure that allows you to protect yourself, and then regain balance, distance, disrupt his fight plan and gain control of the fight again.
When you approach training this way for self defense you focus on structure, movement, and such...not techniques. Techniques will arise our of the structure, but they are definitely secondary.
Again, in my experiences and training in the past, this escapes alot of folks.
BJJ does a good job in this area, but even many BJJ dojos miss the mark a little, however, overall I'd say the BJJ methods at least focus very heavily on "point of faiure" since 90% of the training is approached on the ground with you in a postion of failure and you must regain control.
Too many dojos focus on "parity" that is both opponents start 90% of the time from a position of equality and then one opponent achieves control and then the fight ends.
There are some good lessons to be learned in the parity model, but unfortunately many students (and instructors) begin to see this as the "fight plan" and base all training success on this model.
It goes out the window when we talk self defense mostly because self defense situations I believe DO start with the element of suprise acheived by one opponent (think Ambush), and the other guy is WAY behind in the situation (think OODA) and must work from this bad, bad position and acheive control again.
To me, it has nothing at all to do with technique, alot to do with learning "whole body principles/structure", and everything to do with the situational environment (aliveness) that you inject into the training environment.