I don't know how much you plan to carry, but there's more to buying a pack than how much it weighs. An ultralight pack will weigh two pounds or more less than a "traditional" pack - but much of that weight savings often comes at the expense of the suspension. There's nothing wrong with that - just don't expect an ultralight pack to carry a 40-pound traditional load.

Ultralight packs are usually designed to hold and comfortably carry a load of ultralight gear. That means things that are more compact, and the maximum weight it's designed to comfortably carry is perhaps 25 pounds. If you try to put a 40-pound load of bulkier gear in it, you'll end up with a hipbelt that will buckle or slip, and a suspension that will collapse and never let you get the weight off your shoulders.

The reason those other packs weigh two or three pounds more is that they have a beefier suspension designed to handle the load - way overkill for an ultralight load. Match the pack to your load.

You probably already knew this. It wasn't my intention to insult your intelligence; if I did, I apologize.