0306 cap, capacitive bump. 0603 cap, inductive bump. No surprise that the 0204 is best. In the 25 ps sort of domain, on FR4, there's no need to buy exotic caps.
That 0204 is a 0.47 uF 16 volt cap. With 9 volts DC bias from my distributed amplifier, it loses 80% of its capacitance.