Before chancing upon this thread, I'd never seen a single moment of "Still Open All Hours" but, inspired by the controversy, I've just watched 15 minutes of series 5, episode 6.
The cast appears substantially to be geriatric but, if you can forgive that, it seems to be pretty good stuff. There are some very famous faces on show and the script is relentlessly funny. All in all, for what it is, you can't knock it.
Is it as good as Ronnie Barker's original? That's a matter of opinion but, in any event, it's not a matter that need affect our enjoyment of the show. It seems to me to be a natural and entirely acceptable continuation of the original Ronnie Barker series. Whether it's better or worse, the fact remains (in my opinion) that it's a commendable sitcom in its own right.