Look at dave-jones recent video with impedance analysis, he tests ceramic and foil capacitors of various kinds to see the curves.
It looks like ceramic and foil are pretty similar resonance points, but you would look for microphonics, dielectric soakage, leakage, voltage coefficent of capacitance, surge current ratings (how does ceramic compare to foil, I am actually asking) and other parameters you might find.
I am kind of thinking actually, it might be better to use a foil one, especially if you are post regulating a switching supply, because that might have some mechanical vibration that can bypass your regulator and enter through your (ceramic) capacitor. The PCB is effectively a mechanical acoustic shunt and the capacitor is an energy converter.
I would like to know how to devise a measurement quantifying the conversion efficiency of capacitors to vibration.
I think you can put mirrors on all three axis to measure the vibration of the capacitor and use its mass to quantify the energy present. I wonder if there is a simple accurate method. And how energy conversion in ceramics acts (does vibration on 1 axis only get converted to energy? Do vibrations on other axis effect it (or the energy absorption of the primary axis if so) and testing the frequency response.