2.5 or 3 way; why one over the other?

Thanks for the link but the info there doesn't really speak to my question.  I understand that a better quality 2 way system may well sound better than a lesser quality 3 way.  I was asking about systems from the same manufacturer, in the same product line series, presumably using the same quality drivers, crossovers and other components, and having a modest difference in price.  What, typically are the differences that would tend to cause you to choose a 2 or 2.5 over a 3 way, or visa versa?

tatyana gets my question.  I appreciate all the info on the technical differences between 2, 2.5 and 3 way systems but I live far away from any place to audition speakers, let alone ones from several different manufacturers; so, when I see (in print) the description of any particular company's  speaker systems in the same series (price point) and they have both a 2.5 and an 3 way, otherwise similar in size (may vary an inch or two in height) and construction, and a few dollars difference in price, what should I expect as a difference in sound between the two. In your collective experiences, why would one tend to prefer one over the other?   A typical example is the Dynaudio Excite X34 and X36.