[pct-l] Sleeping bag selection. Ahhh!

[Ben Ulsh]

Hello Everyone,

I am planning a PCT thru hike for 2013 and I am trying to get a jump on
preparations.  I am drowning in choices for sleeping bags and can see
benefits to carrying a 15 deg bag as well as a 0 deg bag.  Is a 15 deg bag
going to keep me warm in the Sierras?  The popular choice seems to be the
Marmot Helium and the Helium membrane.  I am also looking at the Western
mountaineering Apache and the Versalite, as well as the Montbell U.L. Super
Spiral Down Hugger #1.  Does anyone have any experience with any of these
bags or recommendations on temp ratings.  Also, Sleeping bag liner,
superfluous?  Can't decide.  Thank you all in advance to everyone!!  What
an amazing resource!

-Ben