State Street Vs Santander

I've recent received job offers from State Street as a securities valuation intern, and Santander as a FP&A intern. I am having a little hard time figuring out which to pick up on. I've worked at State Street before. Although it was somewhat boring, the environment and the coworkers were helpful and fun to work with. Although I've never worked for Santander, I do have a brief FP&A experience from a different company. I am looking for a reliable, also the most beneficial postion. With State Street I have a very high possibility of staying for as long as I want and staying full time after graduation, but I can not say the same about Santander with any certainty.
Any input on which role or company I should consider more and why?