Re: Aikido does not work at all in a fight.
I tend to agree with Jorgen's comments concerning knife attacks. If it is your time, well it is your time. People watch too much TV and base their ideas of what will happen on romantic ideas of battle and scenarios set up to entertain us.
I think Ron Tisdale also brings up some very good perspectives.
Study aikido for what it is. If you are really concerned with Scenarios based or reality based training, then you should work on those scenarios and develop strategies that work best for them. Don't waste your time studying aikido cause you will learn alot of principles that, while applicable won't necessarily develop your ability to be good at that "crap shoot" scenario.
Aikido to me is sort of like MBA school. You learn alot of practical theory, but understanding/demonstrating theory...and being able to employ it in the "real world" is a totally different ball game...one that requires experience in the real world...not necessarily the "school house" or dojo.