I think I remember someone saying that The Roxy struggled to get decent performers that would be willing to make the trek up to Newcastle, when they could easily pop to TV Centre on a much more established show.
I said this, on an article I wrote about Top of the Pops for Offthetelly nearly twenty years ago now, and which is still cited on The Roxy's Wikipedia page (it was also regurgitated at great length in an unauthorised biography of Fearne Cotton I once read in The Works). I'd still stand by it, although of course in those days pop stars would be used to traipsing around the regions because the ITV regions and big local radio stations were still a thing (indeed, I remember in The Roxy book, which used to be in every charity shop in Britain, they mentioned The Christians arriving by helicopter as they'd come straight from filming Hold Tight at Alton Towers).
I know the Tyne Tees production team had huge respect from the artists (as did Gordon Elsbury, as you say), so many artists had a great time there. I remember there used to be a regular column in Look-In interviewing the artists on The Roxy and I recall The Housemartins said they were excited to go because they assumed it was a real old theatre, and were disappointed when they found out it was just a studio. But the difference between The Tube and The Roxy is that on The Tube you'd be able to play a number of songs, and the audience were active record buyers, so it was well worth their time going there, which wasn't the case here. And of course it'd be in the same week as Top of the Pops most of the time.
As I say, The Roxy wasn't so bad, but it turned out nobody really needed a second version of Top of the Pops playing the same records and going after all the same acts, especially not on primetime ITV which certainly then had a very old and conservative audience. Although I watched it regularly for the last few months when I had my own telly and could watch what I liked, for the first few months the rest of the family certainly weren't that bothered, while we still regularly watched Top of the Pops. One of the few times we watched it during 1987 was when Star Trekkin' was at number one and we couldn't wait until Thursday to see the video on Top of the Pops.
I see show two has already been blocked.