I finally got this build as finalised as I want it to be. Recent changes since the last update are the USE seatpost with purple clamp, Dura Ace rear mech lightly purplified, Dura Ace 7700 12-27t cassette, XT M750 front mech, XTR M970 shifters, XT M770 crankset, Avid Speed Dial SL levers, and Avid SD7 V-brakes. Also some ultlralight bar ends.
Weight is now down to 8.48kg as pictured, which would be pretty much 8.4kg exactly (18.5lbs) with the bar ends and Garmin mount removed.
It's super-fast on the road (great small gears for steep hills in the area!) but I also have a spare wheelset (X517s on XT hubs) set up with the same ratio cassette and the Kenda Klimax Lite 345g tyres for a quick switch to an offroad setup.