Hard core! What are you down to, 20-25 lbs? I'm sure you are lightyears ahead of me, but I'll relate what I did recently.
I tried Mirror to Moon summer of '06 with a group of scouts and their dads...half the group had serious blister issues so we made a change mid-week. Anyway, my pack was WAY too heavy at 70 lbs, but I had 20 lbs of stuff (locater, pop, big tent). I'd read a bunch of ultralight stuff, and was trying to have it influence my packing, but in the end, I just ended up taking more junk.
I could have cut it to 45-50, but I really don't know how much less I could have beyond that. As it was, I was cold on a couple occasions, and was hungry for more carbs almost every day.
I'll be doing this in a couple years again...will go MUCH lighter next time (50 max). And I'll be in a little better shape: more prep hikes at altitude, more interval training, and more time with the pack on my back. A 50lb pack would have been very manageable.
As I recall, I had food left that I wasn't hungry for plus one complete can of fuel. My pack was bigger than it needed to be. The tent was big at 8x10 and the weight was meant to be split between 3 people, but that didn't work out. I carried a nylon hammock which was nice...but I'm don't know if it was worth the weight.
I only had 2 pr pants (nylon zip off), 2 shirts, fleece, and rain gear. 2pr socks. Swimming suit. Sandals (woulda coulda found lighter sandals, but wouldn't have done without) I washed my clothes at the end of each day.
Dehydrated food that I shared with my kid and we still had stuff left. We had trail mix left too. We went through water like crazy...and it was a pain to purify (I carried a pump, my kid carried a filter bottle).
Sorry if this didn't help you...but it did help me (got me thinking about it again)