I have Bypass Tinned Copper.
They sound very tonal reach, vivid and musical.
I never tried Bypass Silver. But most of people like them a lot.
According Jeff:
http://jeffsplace.me/wordpress/?p=12323"
Now comparing the 0.01uF caps in context: The Sn-Cu sounds more vivid and colorful, with more emphasis on the first attack of a note in the upper mid-range (which aids things like melody & beat), the timbral textures sound a little more “real” to me, and more nuanced. They also “open up” the music in an intriguing way, and seem to amplify the “acoustic roughness” of music a little, which provides more emotional engagement. The Ag bypass caps sound smoother and less dramatic, are more elegant and softly nuanced, with a more laid back and distant presentation, a little bit like you’re listening from mid-hall instead of the front-hall like with the Sn-Cu."