Should I stay (SF) or should I transfer (PE)?

I'm looking for some opinions on this.

I finished my 1st year MBA and am working in Structured Finance this summer. I'm a career switcher, and this internship has allowed me to gain a lot of fundamental skills and experience in finance. The directors whom I'm working with have given me a lot of opportunities to get my feet wet. Most importantly, I'm involved in two live deals, each is over $500 million, and I can leverage this on my resume. Although I'm working as a full-time for 3 months, there isn't just enough time for me to learn everything about Structured Finance.

In Fall, I have an option to return to Structure Finance as a part-time (non-paid though) while I'm back in school and I know that they need people to do grunt work. At the same time, this firm has a PE department in which they act as a sponsor. This department also needs part-timer to do grunt work.

I'd definately want to try out PE to get skills and experience in different area. This will not limit myself when it comes to finding a full-time later. Doing so, I will have structure finance and PE experience on my resume, making my profile better. On the other hand, I feel that there are still a lot for me to learn in Structure Finance. I believe that the more time I spend in this dept, the more knowledge that I will gain about structuring a deal. Given that I'm a career switcher, I'd like to learn as much as possible to make myself look like a pro and not to be seen as someone who knows just the basic stuff, which I can talk about high level stuff during a job interview. What would the directors whom I have worked with think of me if I jump boat? But you know, I do learn a lot this summer, but I don't get paid. What more do they expect from me? I'm delivering high quality work. At the same time, I don't want to burn bridges. Shouldn't they be considerate about my situation?

I just want to hear what you think. that's all.