I miss a weathered cockpit
The aircraft I work on presently in the real world were all built in the late 1950's and early 1960's. Their cockpits tend to vary from "hey, wasn't there paint in here once?" to something close to "pristine", depending on how recently they were overhauled and which unit they belong to. What really makes it for me is variety; I keep my modern airshow birds in FSX with clean cockpits, but I like a good worn in (or, occasionally, worn out!) cockpit in my old warhorses.
I do agree, though, that having signs of wear in a cockpit really makes a difference immersion-wise. Perhaps my favorite finishing touch I've ever seen in a good cockpit repaint was in the Accu-Sim cub; someone did some paints with very faint boot-prints on the metal flooring.
Commercial Instrument Single/Multi-Engine Land. Police, Fire, & 9-1-1 Dispatcher. MAINEiac Crew Chief.