I use an Osprey Aether 60L. As mentioned, this is not an ultralight, yet lighter by a wide margin than some monster packs.

This was step 1 for me in lightening up. Usually, one would buy the pack last; I constrained my greedy lazy and luxury-minded self to this size max, and found that I love it. I shed from 50 lbs to 35 on my average multi-day treks, so stage 1 is complete. I'll probably stop here because I'm satisfied; I have tried true ultralight packs, but my back hurt....the Osprey hip belt and frame feels like orthopedic supports - takes less energy for me to use...

There is a sleeping bag zip on the bottom but I use it for varying purposes depending on weather and my intent. rain gear is at the top of pack or on outside with my water filter. Tent is on outside bottom or middle, usually, thought I can fit it in the pack. As with the others, I want my tent accessible without having to unpack anything.

Truth is, I rarely use the bottom zipper; I seem to keep things better organized by going in through the top. The top compartment keeps things I use on the trail, like lunch, small hygiene items, map and compass, leatherman. I use the hydration compartment for water. I have my fuel bottle in a side pocket, and there's one use for the bottom compartment, a cook pot with stove and tea bags. I can stop trail-side and heat up some beverage or soup without unpacking the pack except for the compartment at the bottom. Still, I find I don't do that often because I focus on walking and prefer just water and trailmix snacks during the day; don't like being too fussy.