It's really hard to tell from the article just how different it is. You've got Kathy Kennedy saying "I’m not even sure there’s another one quite like it.... It’s that rare." But then you've got them talking like it's exactly what anyone who watched the film from 1977-1980 would have seen. Maybe it's just that the print quality was rare in light of George's occasional purges?

The headline also oversells how "bad" it was. This from the article (with adequate context) felt more on point:

“I felt like I was watching a completely different film,” wrote Robbie Collin, who called the print a “joyously craggy, grubby, stolidly carpentered spectacle” that “looks more like fancy dress than grand sci-fi epic.” “Every scene had the visceral sense of watching actual people photographed doing actual things with sets and props that had been physically sawn and glued into place. The slapstick between C-3PO and R2-D2 looked clunkier, and therefore funnier; the Death Star panels were less like supercomputers than wooden boards with lights stuck on, and so better attuned to the frequency of make-believe. It felt less like watching a blockbuster in the modern sense than the greatest game of dressing up in the desert anyone ever played.”

To the extent it's relevant, Mr. Collin is also juuust young enough (born 82 or 83) to have missed all three OT films in their original run. For the record, I saw ROTJ first-run as a little kid and it remains the one for which I am the most irrationally protective. This would be as opposed to The Last Jedi, which is the one for which I am the most defensibly and objectively protective. Pardon me while I retrieve my asbestos suit.