Electrolytics have to be oriented correctly, anode/cathode.
Box Film caps' orientation doesn't matter.
Some people think box-film is higher fidelity, less noise; IIRC the box film caps are less likely to leak DC through them.
Box-film are limited in range, most brands topping out at 1µ (I have some 2µ2, Wima go up to 4µ7), so if you have something needing really large capacitance then you're stuck with electrolytics or tantalum (I use tantalum for their space-saving and they're less likely to leak than electrolytics).
Some people say tantalum sound better in the audio path than electrolytics, others disagree.
Stuff that a scope can pick out may or may not be noticeable to the human ear and some people's ears are better than others and some people have a more vivid active imagination than others...
BTW, I haven't looked at the Fordoble boost & drive circuit yet.
