Mine went walkabout. Or rather, lent to a friend that went walkabout.
I liked them. Of the art, Adrian Smith's remains that fondly remembered, there was something characterful and disturbing about his use of the medium tones of pencil. I could live without the Ian Miller spiky spikes with added curly spikes, and am inclined to agree with John Blanche's art teachers assessment of his lack of talent. Given that it's art not illustration and a particularly messy type at that with dodgy perspective and nigh on everything wearing torn fishnets and greasy fur, all rendered in vomited black, red and white ink.
The content of fluff background back then was interesting. The settings were still an ongoing development. There's ideas in them that ain't been visited since, with each new edition having sequentially less fluff background on offer. The Rogue Trader I still have has content about the previous ages of mankind ensuing editions let fall by the wayside.
I ain't terribly bothered I ain't got my RoC books anymore though. What with the settings being developed. The good info, included that worked in after the RoC books were written, makes an appearance in the Liber Chaotica books (if you can navigate the overused handwriting fonts that look like a troupe of spiders have danced the Macarena over Blanche's palette).
One oddity I recall. With the detailed background in Rogue Trader to later editions, jarring against that were rules for Robots. Cool rules, one had to program them before a game with a flowchart of commands, a bit like programming in the Amstrad/Spectrum/Commodore era. Still, flies against the background where such constructs brought trouble to the Imperium and their use got outlawed.