I emailed Mr. Ayoob a few hours ago and I got this reply:
"Aikido is great for threat management and self-defense.
1. Expressly geared to work for small people against large people.
2. Impact is dependent on too many variables; the leverage that is the core of Aikido is an immutable law.
3. A punch in the mouth looks vicious to the witnesses, and can easily cause $25,000 costs in maxillo-facial reconstruction before you get into "pain and suffering." An Aikido thumb-lock leaves no artifact unless you have to break the thumb, and it looks to the witnesses as if you're helping the poor drunk to get to the door without falling down.
4. A little research will show how heavily modern handgun retention training, disarming training, and police defensive tactics (unarmed control and arrest techniques) rely on core Aiki principles.
You damn betcha I believe in Aikido. No one art is everything, but Aikido contributes a disproportionately large share of what works in most real-world situations.
I hope this doesn't open another dimension of argument here, I was just impressed he answered so quickly.
So, now it's finally settled: Aikido does work in a fight. Phew!!