I’ve used VCaps in my preamp - they are super neutral but take a very long time to break in. If you have a cable cooker, you can shorten the time needed, but until you have at least 100 hours, it will sound thin or have a glare, then it settles down.
I did not opt for VCaps in my amps, choosing the Mundorf Silver/Gold Foil oil caps. They had a shorter break in period and sounded a tad dark at first until settling in after 50 hours. They have a rich lush sound that I enjoy.