The ww brakes I mentioned were negative G not zero G. The negatives have beefier arms and a reworked funtionality. It made them a bit heavier, but vastly improved caliper return, centering, initial braking force, and subsequent ramping. I'm pretty keen on getting some. This is partly due to the fact that such a Si-Fi looking caliper would look great on a BMC though.
BTW that stem looks seriously sexy on the S6 front end. I can see why you would'nt change it.
If you're swapping brakes, bars etc. Why not just swap to nokon/ aligator cables.
http://cgi.ebay.co.uk/Ciamillo-Negative-G-Titanium-Brake-Calipers-/180625102452?pt=UK_sportsleisure_cycling_bikeparts_SR&hash=item2a0e185674
£166.66 at the moment SF- what qualifies as a good deal for these?