Hi bomd, it's been about 4 years since I heard the Diamond's and it took me about 30 seconds to know they weren't for me. There was nothing interesting about them. Granted, most of my experience is with vintage speakers. But I have heard modern speakers I liked better.
The Wharfedale's also seemed one dimensional and somewhat lifeless. A few days before listening to the Wharfedales, I auditioned some the Epos Epic 1 speakers. The Epos had a more natural, crisp presentation, that was nice with simple acoustic material, but as soon as it needed some guts for rock, or anything with solid bass, forget it. Right after listening to the Wharfedale's, I went into a different audition room and heard the Harbeth's they had. Don't remember the model, but boy, those were amazing! I didn't ask how much, because I knew I couldn't afford them. They brought the Quad's in to the room and it took me about 10 seconds to know they were for me. I brought Muse "Second Law" (CD) with me because of a few songs I think really test a speaker. The songs are "Madness", "Survival", and "Panic Station". I'm sure you have music you know well that will help you find the right speaker, if you decide to only buy what you can audition first.
I owned the Quad's for awhile, but I also had the Vandersteen 2C's and JBL L65 Jubal's ... I listen to a lot of rock, and some jazz, and blues. While the Quad's were really nice, I had to sell something, and they couldn't compete with the Vandersteen's on most material, and I knew at the time I would be selling the L65's.
I think the Quad's are the kind of speaker you can easily sell and get your money back out. They are more exciting in what they can do for the price, and their size. I know there are powered versions, but there is something about that I don't like ... I assume they are de