Well, the Classic Series shot many things on location around Britain. The BBC quarry was only featured as a quarry on Earth once, as I recall, in The Hand of Evil. Many heavy industrial plants were featured, including the exterior shots of at least one nuclear plant.
So I'm not surprised or upset that they shot this episode on location.
I did find the present-day weapons jarring. I guess they blew their budget on that many Ood costumes and the CGI Mother Brain.
I recently watched part of The Creature From the Pit, and a quote came to mind while watching this episode [paraphrasing]:
"You held him in a pit and threw scientists at him! Of course he's angry!"
I thought the whole thing with the song moving Donna to tears was too melodramatic. Like their soulful gaze into each others' eyes before they blow Vesuvius last episode. I wanted to shout Get on with it! cause there was plot to be had.
We watched this episode with my wife's mother because our power went out yesterday around 8:30. When the Ood started brainsucking and it turned out they had a giant brain held in a pit, neither I nor my wife could hold in the "Squid thingy!" comments, which unfortunately confused my poor mother in law.
Also, the poor Asian Indian woman getting zapped: That felt cheap and retaliatory. Yes, she revealed the Doctor and Donna to the guards, but the guards knew as much as she did what they were doing to the Ood and were as wilfully blind. The only difference I saw was that the Doctor failed to convince her to do the right thing. I don't think, therefore, that there was anything more than blind fate in her death. If it was supposed to be karmic, I felt it was forced.
Anyway, it didn't top The Fires of Pompeii, but it was a pretty amusing romp anyway.