It depends on what you want to do with your life and career. You haven't said what your interests are or what your Master's is going to be in. If you want to be a software engineer then starting career early is better. If you want to go into research then going to university is better. If your Masters is going to be in liberal arts then your prospects of a lucrative job out of Cambridge will be less than having gained two years of professional experience. Since I don't know the specifics, I'll give general advise - decide what's important to you long term and choose the option that aligns with it.