Why would one choose a particular advisor, other than having shared interests?
Many don't speak about this too often, but with an advisor you are not only choosing a field of interest, but you are choosing a mentor. By all means, you want to "tick well" with him/her. There is not much good for a PhD student having a star researcher advisor whom they see once in a quarter and who is a sociopath on a personal level (this is a bit too extreme, but think about it as a continuum between extremes). Choose somebody with whom you will be able to work, whose example it is worth to follow, from whom you want to learn, not only the scientific stuff, but also workstyle, level of quality he/she strives for, etc. These soft reasons are often more important than anything else. For highlighting of all the examples of stuff you don't want to fall into (but will anyway :-) ), go and look at the PhD Comics.

P.S.
I am speaking with a European-centric attitude, where you choose your advisor, since he/she will be your boss, rather than being assigned to one as it seems to happen in the US system. Still, the point is worth to consider. Germans have a good term for this, your PhD supervisor is your "Doktorvater", i.e., "doctor father". That very much speaks how the relationship should end up in an ideal case.