Your educative comments are always appreciated T7!
Just seeing the word "Dark" (let alone the explanation of it) gives me an immediate feeling of non-transparency. For anyone who is interested, here is a piece on the Chi-X... http://blog.openmarkets.com.au/what-is-chi-x-and-how-does-it-work
I found the only comment right at the bottom very interesting. I note Mr Salter also uses the word "conspiracy". So, I am not alone afterall....