I haven't had a pottery barn couch, other PB furniture though. Your couch even "looks" hard! Possibly soften with use? If it's 110% different than the store model, I'd "demand" (nicely, but firmly) insist you were delivered a sofa that doesn't in anyway resemble the one on the show floor. Sounds like you may be looking at trying to exchange it(?). Best of luck to you!

This is normal for furniture. I think their furniture cushions are solid core foam which means no springs nor down layers inside. What happens when you go to sit on the floor models is you are feeling a worn-in cushion from the trial sitting everyone made before you. Solid core foam (or higher density) foam is good for spring-less cushions because the foam does not break down or soften easily. It means you won't have to replace it sooner. I would take it up with PB and ask questions but it's like buying a new mattress. You test the one at the showroom and get a stiffer one. After 30-45 days, it should soften. Give it time and see what happens. You may want to mention that it helps if they have the fine-print on the softness of the sofa. It should have been properly disclosed before purchase...