[pct-l] Ultra Light Backpack Pros and Cons

[Russell Mease]

I think most on this list are of the ultra-light crowd.  I am leaning in
that direction for certain pieces of gear (just purchased a tarptent notch
at 24 ozs) but for other pieces of gear, specifically the pack that you
wear every day and thus is the most important for comfort of your trip, I
am curious about the pros and cons of using an ultra-light pack, such as
the ULA and GoLight packs.  I currently own an Osprey Aether 70 which
weighs in at about 4.5 lbs.  As I'm looking into the Osprey Exos and other
light packs, and as I read people's experiences with these packs on this
forum, I am constantly reading things like, "lasted 500 miles and then had
to replace", "the strap broke...", "it got ripped up in the desert
section", "had sore shoulders because most of the weight rested on my
shoulders", etc....

Here's my question:  Is it worth having a lightweight pack if you have to
suffer carrying 25-30 lbs with in-adequate support and a pack that will
have to be replaced every 500-1000 miles (at $150-$250 a pop), sore
shoulders, sweaty back because of no ventilation, etc....  Or, is it wiser
to go with a more traditional pack like the Aether, sacrifice some weight
(but stick to light weight gear for the rest) and be able to carry your
pack in comfort and the pack will last the entire thru-hike and most likely
many more years of use?

I am just curious if anybody has regretted going with an ultra-light pack
because of these issues.  I am planning an estimated base pack weight of
about 20 lbs (including the Aether) and expecting 35-40 lbs full pack
weight.  My gear list is here:
http://russmease.blogspot.com/p/pct-gear-list.html

Thanks for your reply!
Russ Mease