NPO/CGO ceramics are probably the best capacitors you can buy. See Cyril Bateman for details. If the value/voltage/size is right, use them.
Resistors need to obey Ohms Law under all operating conditions and capacitors must meet
I = C dV/dt
Apart from problems with soldering, polystyrenes are microphonic and the way they're made means even 1% bits have poor distribution. At Calrec, we once stripped every single small polystyrene from a 72 channel Broadcast Desk and replaced them with NPOs.
Silver Mica, the Golden Pinnae darling, has "high" loss. Replacing the input ceramic capacitor in a condensor mike may increase noise. Scott Wurcer will show measurements in the next issue of Linear Audio.
For EMI protection, size matters. Big "film" caps are good aerials to pick up crap. A common mike "improvement" is to replace electrolytics or ceramics with huge films. This often results in RFI.
Capacitors at a mike XLR need to be 10n+. Unfortunately, you can't get NPO/CGO ceramics that size. But the advantages of small size and good RF outweigh the poor dielectric of non-NPO/CGO ceramics compared to films.
However, if you can hear the slight midrange roughness with these, Cooktown Recording & Ambisonic Productions has Golden Pinnae capacitors hand carved by Virgins from Solid Unobtainium. Send $100 in used bank notes for a sample.