I am certain I can tell the weight difference between an Ecrin Roc and a Kask. I had an opportunity under the Ecrin to do some pole saw work that kept my head up all day. Its just a /little/ neck soreness, doesn't bother me /that/ much, and only when I look up.
On the other hand, I just belayed the Speed Climb for TxTCC in the Kask-- lotsa hours looking at a high angle for the two days, no neck strain.
Chin strap? When one end of that branch comes down and tugs on the helmet, I don't have the free hands or time to put the brain bucket back on before the other end of the branch clobbers me.
So far, I haven't any rash or bald spots in my beard from wearing a chin strap. Still hoping.
I saw an older kevlar (Pacific) helmets folded like a used bottle cap. Didn't survive the battle in the back of the pickup with the loose toolbox. The longevity of a helmet likely has more to do with how its stored than when it stores your skull.
And the clincher for 'mericans is that Uncle Sam likes you to spread that money around-- and will give you a little break on your income tax for purchasing such items.