I appreciate Frederik's candor but I wish there had been some sort of acknowledgement prior to this that the CAST caps do not all sound the same. At least this would help explain different reactions to them. For example, I have stated in this thread before that my two 630v CAST caps----the .47 and 1.0---sound different. The only visible difference in their construction is the different type of leads: the .47 has solid wire that is silver in color and the 1.0 has stranded or pleated copper. I had always assumed the differences in sound between these two are due to the different leads. Now I have to wonder if the caps may be different inside as well.
I have never compared the 630v caps to my 100v caps in my speaker crossover, but given Frederik's statement above that they use different construction, I suspect that may explain why I am much more happy with the 100v caps in speakers than I am with the 630v caps in my electronics. In my totally arbitrary ranking, I would give my 7.5uf, 100v CAST cap a 9, the 1.0uf, 630v CAST an 8, and the .47uf, 630v CAST a 6.