C0G vs polypropylene capacitors in signal filtering
Take this as a not-so-comprehensive comparison:


For C0G (NP0) capacitors, you only have a choice of less than 0.5 uF capacitors, There are not many higher-capacity C0G capacitors, and with an increase in capacitance the price increases accordingly. but with polypropylene capacitors, you have a wider choice higher capacitance and voltage.
Polypropylene capacitors are available chiefly as leaded components. while you have the chance to find ceramic capacitors in different SMD packages.
Both types have quite linear frequency and voltage responses, but this is just a general term and for a specific application, characteristics of parts must be analyzed.


Overall if we put spacing problems aside I would choose polypropylene capacitors for highers capacitance and C0G ones for lower capacitance.