Famous professor at relatively unknown university for post-doc I am about to finish my Ph.D. soon. It was in the field of computational sciences and was done from a well-known European research lab. In my own assessment, it has been a mediocre Ph.D. for me (2 paper in top tier conference, 2 in average ones, no journal yet).

I am looking for post-doc as the next step. I already have a couple of offers for post-doc, and one of them is from a famous professor in my field. However, he happens to have setup his lab at a relatively unknown university in a small city in central Europe. 

I was obviously aware of this while applying, and I honestly thought this wouldn't bother me at all. However, now that things have moved forward and the time has come to finalize a decision, I do find myself a bit bothered with the stature of the university. I have tried to seek advice on this matter from my current Ph.D. adviser. However, she knows my prospective post-doc supervisor in person and has been offering highly diplomatic suggestions about the matter.

So I thought it might be a good idea to ask this question over here. Please share your opinion on this. How much does the stature of the university matter in a post-doctoral position, given that the particular lab I am going to be associated with is headed by a famous name and the job description seems to suit my research interests quite well? I have other post-doc offers from relatively younger/less-famous professors from better universities. Given that the area of research is more or less similar in all the cases, what is more advisable for a career in research?
Just opinion, of course, but I would suggest that a great professor at a small school, no matter its reputation, would be a huge asset. You will have a chance to work closely with a mentor that you wouldn't get to do as well at a larger place. I realize of course that size and reputation aren't necessarily the same. 

But it is the letters you get from the professor if they are well known that can set you off on your career and, if you do get the chance to work closely, that association can pay dividends for a long time. 

While a degree from a prestigious place has value, I think a postdoc with a leader of the field is a great asset. 

And, of course, "relatively unknown in central Europe" is itself relative. Lots of people don't know about, for example Charles, and such, depending on where they are from.