Just to add some background, I have already received offers from the 2 universities, and I'm trying to choose between the 2. Both offers require the same grades, so I will likely not be selecting either as my insurance (for those of you familiar with the UCAS process).
Congratulations.
I didn't like the general atmosphere of Cambridge when I went for the open day and the interview. I'd also hate to be living in an environment where I'm surrounded by historic architecture.
I suspect there's not much of a "campus atmosphere" in central London. Do take the time to research what it is like from the non-course aspects; they are important too. I believe "The Student Room" has much information, but I suspect it will require you to quickly develop the skill of working out
why X said Y, whether it is true and whether it is valid for you.
The purpose of my original question is to ascertain whether Cambridge is better than Imperial,
Yes it is. To repeat, no it isn't. Both statements are simultaneously true
and if so, whether the difference is big enough to justify studying at Cambridge despite my feelings about it.
Probably not, provided you are making a choice for "the right reasons". It is, of course, up to you to choose the right reasons. (I must admit to being a little concerned that the architecture isn't a sufficient reason.)
FWIW, much to my headmaster's annoyance, I chose not to go to Cambridge, and chose Southampton instead. I'll never know whether that was the better decision, and I wouldn't presume that my reasons then apply to you now.
I later worked in Cambridge and thoroughly enjoyed it, but eventually the lack of trees and contours became oppressive!
Good luck with your choice and career.