I've wanted the D2 ever since I heard it in Proac's room at CES '08. Unfortunately, I can't afford a pair of those. I could, but then it's hard for me to justify the purchase.
As for build quality, there is more to it than just a pretty cabinet. Build quality plays a huge part in the overall sound of a speaker, which is one reason why Proacs sound so good. Also I like the fact that Proacs are hand-built in England, as Sonus fabers are in Italy, and they use excellent products to build them with. I'm willing to spend more for that simple fact.