yeah the silicone caps are totally on another scale, both in price but also in tolerance and repeatability. I think Vishay also offered some reflow solberable ones a while ago but they were discontinued. Accu-P would also be my go-to if price isn't an issue. There are also some very high frequency low C caps that intentionally use miniscule amount of lossy dielectrics (X7R et al.) to avoid sharp resonances due to the package parasitics (DLI, I think there under the Knowles brand know)