Got a job offer from Goldman Sachs... but still undecided?

Here's a succinct-as-possible explanation of my situation:

I am a 25 year-old MBA from a mid-ranked school in the Midwest. Passed CFA Level I. To offset the young MBA, I did constant professional internships from halfway through undergrad, all the way through finishing the MBA - in areas like accounting for a real estate investment company, to buy side credit research for an insurance company, to due diligence and consulting work in the VC/angel investing space. I also taught an undergrad Personal Finance class during the MBA. In other words, I don't have the typical story of a Wall Street person or an MBA, but I have some decent experience.

I'm currently working at a small startup-y boutique that does outsourced financial/accounting services for private funds (VC, private equity, real estate, etc). With my entrepreneurial background, I'm helping the founder launch a new segment of the business where we offer accounting/financial/CFO services to established startups and small businesses.

...About a month ago I got an out-of-the-blue (hadn't had correspondence in a year) email from Goldman Sachs to interview for a position in credit research. The base pay would be better than I'm making now, but the job I'm in now was a calculated risk, hoping that bringing in lots of new business in coming years will grow my compensation much faster. This would be an entry level Analyst position, with 2-3 year expectation, then the opportunity to move up or laterally.

I like credit research, and having GS on my resume would obviously be huge to offset my young and not-top-tier MBA. But I feel like I'm way over-qualified for this position?

Any thoughts/advice is much appreciated.