are crap, my browser stuffed up and i lost my response.
A very brief summary of what I said.
I have compared the cast pio to the vsf and the auricap.
Both the duelunds are more open and have to myself a more natural tonal presentation.
The cast pio itself has a cleaner sound, with a bit more sparkle in the top end, it also has a more robust bottom end however that may be because I moved from 2.2uf to 2.7uf.
The vsf is much better bang for your buck than the cast pio (at rrp) and I know that some prefer the extra "warmth"