Students leaving a new lab - have I made a wrong choice? I've been accepted to a relatively prestigious neuroscience PhD program abroad and will be joining a new lab (2.5 y/o) in a few months. I've been in contact with a possible PI a few months before applying and was very excited about their previous and current research plans. From talking to their students (at the time, two postdocs, one PhD and one research assistant), I got the impression everything was going very well and everyone was very satisfied (this was about five months ago).

However, in a recent visit, I discovered both postdocs have decided to leave the lab (and also explicitly regret joining it), mostly due to disagreement about the way the research is conducted. I think it might be important to note that we're all pretty sure that the PI has some form of Asperger's, which is evident mostly in communication difficulties. While all of their students stressed that they are a very nice, generous person, who is always willing to help with whatever (and also well-funded), they also claim what was once seen as shyness and introvertness (which can be dealt with) is now being seen as mostly lack of understanding, direction, and general vagueness on part of the PI (i.e., not really having a clear direction of where the lab research should go or a good enough understanding of neuroscience).

The last PhD student and I get along very well, and they claim I shouldn't be too worried and mostly be prepared to work independently; however, I get the feeling they are also quite worried about the situation.

So I guess my question is: have I made a wrong choice? How worried should I be? I'm torn between moving forward with the program, and in the worst case moving labs after a year, and between giving up on this specific lab right now and trying to find other options. As I mentioned before, this is more complicated by the fact I would be moving abroad for this PhD, which includes quite a lot of pre-planning.

Thanks

Some additional information that may or may not be important:


I really like the PI, and we seem to get along well (as much as is possible with them).
The PI comes from a background in Physics, while their post-docs was in neuroscience. They don't have many publications, but those that they do have are in really highly-regarded journals. They are also very open to answering questions, but you need to be very direct in your questions.
One postdocs has a background in physics, while the other in psychology and neuroscience.
The main result of  a PhD program is not a PhD thesis, it is a PhD-level scientist. In other words, you.

Your PhD is about you learning to be a researcher. It's about things you pick up from supervisor and the lab: research methods, writing styles, professionalism, passion, attitude. 

The postdocs in the same lab may have different goals than you, different experience, different needs and expectations from/towards PI. Their decisions are their own. 

For the sake of example, let me exaggerate a bit. Imagine you also had a  college student in your lab, and your PI happened to be a great college teacher, spending a lot of time explaining some basic maths to the student. The student would probably genuinely  benefit from this, but as a PhD student, you could feel yourself a little bit overlooked.  Is not it what your postdoc colleagues might've feel at the moment? Is it possible for a PI to be equally perfect for all members of the lab? To what extent this all-round excellence matters for you?

Maybe, reflecting on these questions helps you to find the right decision. Good luck.