You are obviously planning to stay in Europe/UK since both are UK based programs?
It seems the LBS is a much stronger MBA option/name in Europe than Oxford, which has a relatively new program. Would you agree or do you feel Oxford's historical name is more helpful? I have not heard much from EMBA students or graduates of either programs but what is coming from Full Time students is that the program is still new and has some growing pains at Oxford. Check out the
Business School Reviews.
The Columbia would be a great addition should you choose to move to the US or need to send your resume around.
Keep in mind that EMBA programs do not help with placements or job finding most of the time - they are educating leaders and executives who already have solid jobs, so job and career services tend to be omitted from the program. Other things, of course are very advanced - course offerings, professor choices, and retreats are very much up there.