In reply to dutybooty:
im like you: skeptical.
about 10 years ago i did a course in the himalaya and everyone had them. i scoffed and muttered to the instructor (a guy with a serious resume back to the 70s who some will have heard of) what a bunch of hoodwinked gear junkies they were.
he agreed, but pointed out 'its not that they have them, they just dont know how to use them'.
later he got his poles out as we left lukhla and it convinced me: both poles at walking axe height.
at namche i got myself a pair, under the deal from the instructor that if i didnt lie them by the 3rd day of using them hed buy them and give his old ones away.
35 days later i left them in lukhla, well worn and abused (they were fake lekis).
all said, i have a pair i only use when the load is heavy or its about moving fast thru snow. by example i took a pair up up the baltoro but used them once, for 10 mins on the way out crossing glacier bridges.
theyre useful, but not that useful.
totally they need to be at no more than walking axe height, full extension only in deep snow and maybe river crossings.
for me they are the first thing i leave off the list when weights an issue (and i regularly carry hefty loads).