Well let me say this about that. A Z-rest and a Neoair together probably weigh about the same as an exped, and are just as comfortable (IMO, that's subjective).
And I don't worry about the bulk of my z-rest because it's carried under the compression straps on the outside of my pack taking up zero pack space. And if I'm just walking on trails I put it on the bottom of the pack which is a good thing because it protects the bottom of the pack when I sit down and lean back to take a break.
