In reply to rowancastle:
if your staying at glacier level then ditch the plastics - more comfortable boots will be available. that theyve not been worn much only compounds the potential for problems when you set of on those 10hr days on sketchy terrain where an ill fitted boot with ruin what is arguably the finest mountain trek on earth.
you may only want crampons for the gondogoro la, but even then kahtoolas may do, but a boot that has a rigid shank will be welcome on ice.
theres actually a lot of sand, loose rock and gravel sections on the route, but the stuff up around BP/K2 can be slushy, so something water resistant (ie, not absorbant leather) will be better.
as far as boots go, something from the trango series from la sportiva would suit well.