In reply to Sharp:
Too much. Always... and it seems to get heavier throughout the day
About 1.5 - 2 sets of wires, 3/4 set of tri-cams (in pace of cams and hexes), 8-10 draws (1/2 of which are sling draws, guide plate, slings ,few spare crabs, prussiks etc.
Winter specific - upto 8 screws, cord and threader, two warthogs,s, few pegs (and/or a dead boy and shovel if I think a snow belay is needed).
1-2 60m half or triple ropes (route dependant), helmet, harness, crampons, axes
Hardshell, softshell and belay jacket
small first aid kit, survival bag or shelter, head torch, spare batteries
sandwiches, 1.5L camelback of water and lots of sugary snacks
Split between 2, probably comes in at ~15kg, between 3 it's closer to 10.