Hello Olivier,
Thanks for dropping by.
The difference in sound between the caps is readily audible and not very subtle. The Sonicap is a really clear sounding and neutral caps. Great sound for the money.
The Teflon version (Sonicap Platinum) is "faster" and clearer. More of the music comes through. The caps does take a VERY long time to break-in and will not sound that great during the first month of use. After that things begin to open up and you will be amazed at all the information that you will suddenly be hearing.
The V-Cap is also a Teflon cap and will take at least as long to break-in. I have found the V-Cap to be a bit more "organic" or analog sounding. The Sonicap Platinum can be a bit analytical in comparison. My comment about the V-caps is yes, it's expensive. It is also worth it, sonically.