Antiresonance of multiple parallel decoupling capacitors: use same value or multiple values?
I have a bunch of observations that I decided to make into an answer and please note that I'm quite happy to spend 30 minutes doing a simulation of this if someone can precisely state what the test circuit was that produced the large anti-resonant peaks.

Firstly, I'm not sure that I follow the precise circuit of what was described by Ott. 

Are the 15 nH inductors in series with each capacitor as is stated? If they are then that is clearly wrong because the smaller capacitors will have smaller ESLs. Is there any mention of the resistive loading effect of the circuit the capacitors are "smoothing"?

What are the inductances of the traces that feed the capacitors or, were the capacitors connected using earth and power planes?

In short, I'm not happy with the Ott claim based on the lack of clear circuit that can be reproduced in a sim. If a clear circuit can be made available then I'm interested!