Hello, Jen,
I sleep pretty cold, and don't have much padding on my bones, and am in the older range (64) when folks often say they need to take a big inflatable pad. Last summer I carried the REI Flash I got on megaprodeal (because of the shoulder–ever so much better now, only a little gimpy, I can live with that, thanks to you and Mark!) but it was a big hassle, what with inflating and deflating, patching punctures, etc. I've gone back to my usual CCF pads. I carry them vertically on the back of my pack.
Ridgerest: What I've carried the most for 25 years. Short 48". The old gray ones are pretty flat now; I just lend them out to Camp Fire kids. The newer green and silver one works fine. A little bulky but not all that heavy, 9 oz. I think. Nearly indestructible. There's also a blue and silver one that's a bit thicker, not sure of the weight, I cut it to 48", for colder weather.
Gossamer Gear Nightlight: This is their Evazote one that folds in thirds and fits in the back of my pack in place of the Sitlight that comes with the pack. Pretty good by itself for warm weather. Flattens with time and use a lot faster than a Ridgerest does. I probably need to order a new one. Before it has the life flattened out of it it has an egg-crate configuration. Not sure of the weight by itself, it is just part of my pack. GG has it at 4.55-4.9 oz.
Gossamer Gear Evazote 3/8": For our 2011 and 2012 JMT trips I used one of these with the Nightlight underneath. I cut it to 48". Thinner than the Ridgerest but coupled with the Nightlight it seems just as warm. It deforms more than the Ridgerest but that does not seem to interfere with function. 5.2 oz. cut down. Somewhat less bulky than the Ridgerest.
Zlite: I have one of these, tried sleeping on it once, the hard egg-crate shape was annoying, I gave it to my son, later he gave it back so it is just in the lending gear now.
None of these CCF pads absorbs any moisture that I can tell, shouldn't since that's what "closed-cell" is supposed to mean. The Thermarest ones are firmer than the GG ones. None are as cushy as the inflated Flash, *all* are cushier than the Flash suddenly deflated during the night!! Mostly I am pretty tired at night on a trip, go to sleep at dark or sometimes even earlier, waken during the night but go back to sleep, up at first light. On CCF, I turn often but that seems to be OK. Going back to CCF after using the Flash for a while, it took a bit of getting used to again, but that was OK too. I have not tried any of this on snow, that is out of my range, probably for snow you need more insulation so that might be relevant to your PCT plans.
If you want to borrow any of these to experiment with, let me know.
Mina