I don't see what's wrong with IKEA's layout. I mean, it's bad if you came there to buy a particular something (though in that case, you can just skip the gallery section entirely and go straight to the well-organized shop and warehouse sections.) But it's exactly right for what I go there for: looking through the gallery as a 1:1-scale-model catalog, deciding what you want/need from that browsing, and then picking it up if you still want it by the time you see it again in the shop section. It's destination shopping, in the same way a bookstore is.