Depends on your personal preferences and what your other offers are. Choosing Imperial over Cambridge would be folly, but if your other options are outside the top 10 then Imperial makes sense.
Personally (and I'm not saying you should be the same) I'd choose Oxbridge and probably UCL/Warwick over Imperial. If the other option was something like Bristol then its harder to say, Imperial has slightly better career prospects at the cost of a much worse undergraduate experience. It really comes down to personal choice and what you do afterwards. If you want a high-paying City job then Oxbridge/Imperial/UCL/LSE/Warwick would maximise your chances, but the general university experience also matters. Living in London as a student also sucks, but UCL/LSE are just as bad for this.