If anything it's ROTJ thats the cheap and cheerful OT film.
The one Death Star corridor they bothered to make looked so bad (in comparison) it pointedly features in much of the deleted scenes.


Similarly :


It's more than just the design work it's the whole feeling of epic scale conveyed by the lighting that makes one a classic scene and the other a deleted scene.
The gigantic scale of the ANH sets and the way they were photographed is complimented by the design.
The corridors and conference chamber look like they belong in the same place even though only a few elements overlap.
The same can not be said for the Death Star interiors in ROTJ, where re-used sets (like the Executor bridge) don't look anything like as good as they did in previous films.
Ironically that set contains parts of the Hanger Trooper Station and those elements actually look better in the ESB set than they do in the original film (nothing to do with Gilbert's work there he didn't paint the thing red the first time).