Clearly, based on the comments left here, "Love & Monsters" is a love it or hate it affair. And probably all you need to know going into it is that after 45 minutes you'll likely fall into one camp or the other. I can certainly see why it would rub someone the wrong way, and yet I feel for the DW fan who doesn't embrace this episode for the wonderful stretching of the show's format that it is.
The episode, written by show runner Russell T Davies, is a great example of why he's in charge of the new series: He's an idea man, and unafraid to try new things, rather than simply fall back on the tried and true. Maybe some of his more radical ideas don't work for everyone? Even with the most mainstream episodes, Davies & Co. don't please everyone, all the time. After watching "Love & Monsters", my 13-year old son was so into it he immediately said, "I didn't even notice the Doctor and Rose were hardly in it."
In Season One Davies took some baby steps (the highly underrated "Boom Town" springs to mind); in Season Two he's confident and willing to go even further. "Love & Monsters" is a bright, shiny example of DW for the new millennium. While many have concentrated on its humorous aspects, few mention the episode's melancholy, which for me, was the core sell.
And on top of everything else, it's got ELO tunes. This fan was in heaven.