I thought I would circle back and let you all know what I decided, more than 2 years after you all offered useful advice.
I struggled with this decision. The truth is that there is currently no pack that fills the niche previously filled by my Golite Odyssey, which was 3.5 lbs, carried 90 liters, was good for 40 lbs or so, and had a wonderful, easily accessible and roomy back pocket the size of a daypack. There has been no equivalent for quite a while now, and I found myself putting off the decision hoping someone would come out with a new pack.
I discovered that in order to achieve all that volume at such a light weight the Odyssey sacrificed on durability, and after 11 seasons and approximately 30 trips it was barely held together with ripstop tape and safety pins. I don't mind that, really--I would gladly just have bought a new Odyssey having worn out the old one. But Golite is no more and no one else makes anything like the old Odyssey. And so, after this season when the Odyssey split a second seam, I decided not to try to doctor it again, and this forced a decision.
When I first contemplated replacing the Odyssey, I came close to buying the Osprey Aether Pro, which is somewhat heavier, has less-convenient pockets, but sports a better suspension so it could comfortably carry more weight.
https://www.outdoorgearlab.com/reviews/ ... her-pro-70
But the more I thought about it the less I thought it was wise for my aging body to carry more weight. I ought to be going in the opposite direction and so such a great suspension would be wasted if I kept my full weight to the mid 30 lb range, something I have been edging toward. But it also seems that Osprey has discontinued this pack, so the choice became moot.
The largest pack with the most convenient pockets I could find--which weighs less (rather than more) than my old Odyssey-- is the ULA Catalyst.
It comes in at 3 pounds and carries 75 liters, is rated for 40 lbs. Critically important, it can take a Bearvault 500 horizontally--a key requirement for me. Both packs have two aluminum stays and a plastic stiffener in the back. The Catalyst's suspension may actually be superior to the Odyssey in which I sometimes carried as much as 45 pounds. I will see how the pockets do--it lacks that marvelously convenient back zipped pocket of the Odyssey, but it has a big mesh back pocket, huge side pockets, and usable belt pockets which get praised. The old Odyssey's flimsy side pockets rapidly stretched out and I never could use them, and its belt pockets were too small for much of anything more than a tube of sunblock. So perhaps the Catalyst pockets as a whole will work out just as well or better. The Catalyst's volume does not measure up to the cavernous 90 liters, but the very large side pockets can handle a tent and other long items strapped to the side, so I should be able to make things fit. I may have to make one or two other replacement purchases to get my volume further down. I'll see.
So I have order a Catalyst, which others on this forum highly recommend. I will report from time to time on how it works out for me, in case there are others struggling with my dilemma. What is my dilemma? Basically, I needed something in between a fully suspended heavy load hauler and a minimalist ultralight pack, and there is not a lot in that category. I hope this choice fills the bill, and will let you know.