Interesting Surrogate Bidding Problem

I found this deal to be a fascinating hand, at least for the possibilities involved. See the link to the BBF post. http://forums.bridgebase.com/index.php?showtopic=35633&hl=

This features a 5C call that ends up being RKCB for diamonds despite agreement that spades are "trumps," with the end contract (depending on the answer) being either 5S or 6D. This is enabled because of all the info exchanged during the cuebidding sequence, which follows a 4SF that sets trumps at the two-level. A really powerful auction. Now, admittedly it would be a better sequence as far as the clarity of the position to take) had Responder held three diamonds or the AJ doubleton, but fascinating nonetheless.