Corp. Dev. vs. M&A/PE Tax Consulting

Hey everyone! I would really appreciate help in deciding which internship to take. To give a bit of background, I'm an Accounting & Finance student at a Tier-2 school, but with a prestigious undergrad Accounting program.

This past Summer I interned at a Big 4 doing Tax Consulting in Puerto Rico. My time there was amazing, but the work was not for me to say the least even though it's useful stuff that I learned (tips and tricks on taxes and what not). Despite this, I ended up getting rec letters from the Partner and Managers. In addition, I got to work with the M&A Advisory team for a few weeks in the firm and fell in love with the work they do. As a result, I used my time there to network and see if I can get an M&A opportunity (PR actually has a good network of people doing M&A on the island).

Presently, I'm faced with 2 opportunities to pursue.
1. Corporate Development with Popular, the largest bank on the island which is also considered a top 30 bank in the U.S. mainland.
2. M&A/PE Tax Consulting with Alvarez & Marsal in Miami.

Although this may seem like a no-brainer, here are my thoughts on the situation.
Popular:
Popular will offer me a Corporate Development internship that are very rare to get this early on. However, the MD told me that even if I'm their best intern, if they have no capacity there is no full-time offer (PR job market is very unstable and people cling on to their jobs like it's do or die which is understandable). Although, I can leverage this opportunity post-internship to get a better gig stateside, I'd be graduating within a year and would need to be looking for full-time opportunities. Another pro about Popular is that they have a lot of ivy-league MBA execs that I'll be working with that could give me good rec letters for MBA. That plus applying to B-school from PR would increase might chances in getting into a top-notch program.

Alvarez & Marsal:
A&M is a renowned Restructuring firm which is work that interests me and that I'd like to get my feet wet in. However, my offer with them would be working in their Tax Consulting arm in Miami specifically coordinating with their M&A, PE, and Restructuring teams and clients. I've heard of people lateraling into different teams within the firm and other firms, but at the same token have heard that this is difficult and tricky for multiple reasons (i.e. team already having invested time & resources in you and would look down upon you wanting to move). I really like the environment they have though (work hard and hustle and you'll be compensated as such). In addition, even though I have done Tax Consulting in the past and found it uninteresting, I'm curious to see what type of work lies ahead if I pursue this route and if there are opportunities to lateral into their Restructuring team. On a final note, A&M does have a solid track record of hiring their interns for full-time and that security is a plus over Popular.

For sure at the end of the day, MBA at a top-school is a definite move in the future.

I'd really appreciate any advice on this matter!