I generally agree with you on ultralight packs. They work fine, but are designed to be part of a super-light system, so that everything you carry is similarly pared down. You can't take your AT load, stuff it into an ultralight, and expect to hike very comfortably.
Still, I infer from your question that you hope to lug less than you did in 1990, maybe 30 to 40 pounds this go-round. If so, then there are several lighter packs out there that aren't "superlight" but still offer lots of suspension heft. One of the best is the Mountainsmith Auspex ($260). It's a tough but lightweight (three pounds, seven ounces) pack that has 4,200 cubic inches of capacity. That should be enough to hold what you need while forcing you to pare back a little on extras. If you need a little more room, the Specter ($329) has a very generous 5,600 cubic inches of capacity, yet still weighs only four pounds, five ounces. Kelty's trim Haiku pack has specs similar to the Auspex, but it's a tad bigger and weighs just a few ounces more. And, it's a bargain at $160.
In a similar vein you'll find Gregory's Forester ($250). It's good for 35 to 40 pound loads, has 4,700 cubic inches of room at the medium size, and weighs under five pounds. Not superlight, but light enough.
Think about your 1990 trip to guide the way to an even lighter load. What didn't you need? Look carefully at your basic outerwear setup. Patagonia's lightweight R2 fleece ($145) and Marmot's superlight Precip rainwear ($99 jacket, $89 pants) will shed some pounds, weighing about half the equivalent combo from a decade ago. You also can trim ounces in cookware, with a titanium cookset ($40 for an Evernew cookpot, all you need for one person) and one of the new lightweight liquid-fuel stoves (MSR's Simmerlite is $89). Throw in a Feathered Friends Hummingbird sleeping bag ($255, 20-degree rating; one pound, ten ounces) and you'll find your load getting lighter in a hurry.
Click to see REI's selection of Mountainsmith backpacks.