PNC Corporate Banking (Underwriting) or Boutique Investment Bank

Hi everyone - I am an undergraduate junior that is weighing different offers for my junior year summer. Recently, I received a corporate banking internship offer in Chicago for PNC's underwriting (the firms top underwriting spot). However, this past fall, I interned at a small local boutique investment bank and have a return offer there for the summer - they typically do not hire full time analysts out of their intern class. Since my university is a non-target school with almost no full time recruiting for investment banking, should I choose the PNC offer or go back to the local boutique? And why for whatever one that is better?

Also, would anyone be able to comment the pros and cons of underwriting, the lateral movement it provides into investment banking, exit opportunities available, or applying to a top MBA program in the future?

Thank you to everyone in advance!