I don't mind the real newsroom backdrop that can be found in
N8, or at Sky News, or indeed at CNN Abu Dhabi, for example.
As far as the fake renditions go, for by the worst one I can recall is the one used by BBC World News during the virtual cut glass era, between 1994 and 1997? The wide angled shot they had of the virtual set at the open and close of the flagship bulletins (Newsday, Newshour, The World Today, Newsdesk, etc....) featured a fake implant of the actual newsroom. Yet, when we continued to the head on shots of the Main and co presenters, the newsroom background had disappeared and all we had was the typical blue virtual reality cut class background. The BBC World pages on TV Ark from that era depict quite well what I mean.
http://www2.tv-ark.org.uk/news/bbcworld/1995.html
Midway down the page, you can see Tim Sebastian and Alastair Yates depicting the phenomenon I am referring to, above. (Thanks to TV Ark for the images.)
I never understood the point of that naff idea, as it clearly proved that the background was fake and I thought, why bother!
Yet, for standard BBC World News bulletins, the head-on shot of the presenter DID retain the newsroom background as it's backing. (I can only best describe this as the virtual reality background used when Nik Gowing famously announced the death of Diana. That backdrop was the standard World one of the time).
If done properly and if consistent, I guess fake newsroom backdrops can be very well received by the viewer. Here one minute and gone the next kind of defeats the purpose of trying to pretend there's a newsroom behind.
My far my favorite ever news backdrop was the McDonald/Etchingham launch set for News at Ten when it returned. Why they ever dropped that, I'll never understand. (I know it's not a fake newsroom, so to speak, but nevertheless one of the classiest ever used on tv news).
Rather interesting thread, this.