I got admitted to both schools.
(LSE MSc Quantitative Methods for Risk Management at the dept. of statistics
and Imperial MSc Risk Management & Financial Engineering at business school)
What I found so far is
LSE - more brand-name in financial industry, 10 months long (doesn't include any projects and papers), relatively cheaper tuition
Imperial - structured education in learning programming skills (e.g. vba, python), 12 months long (includes an applied project)
I would look for the financial risk management or actuarial position after graduation in continental European countries.
Your opinions related to the decision would be highly appreciated!