Product Controller or Business Analyst, Which Do I Choose?

I have two offers from two big investment banks; one as a product controller in structured credits in finance and the other one is front office business analyst in IT for exotic equity derivatives area where you will deal with risk and pricing.

What are the carrer prospects for both of them? I am not sure what I would like to do in future however I know that I would like to gain as much product knowledge as I can and have deeper understanding of business. Business analyst position pays 10 -15 k (in pounds) more compared to product controller position.