You are in the market for a pair of new speakers. Budget: around 10,000 Euros. First of all: we are jealous! These are serious amounts of money to spend on a pair of speakers. You simply belong to the lucky few.
In this class you can not really speak of good or bad. It is really a matter of matching and taste. To name a few examples: Focal Sopra No1 (pretty neutral), Kudos Titan 505 (energetic and engaging), Grimm LS1a (active, modular and incredibly neutral) or for example a set of Revel Performa B floorstanders (tends to the Sopra No1 with slightly tighter bass).
Below the measurements for comparison. All at 1 meter, straight from the front with a 3ms time-window.
What’s the best choice? That’s up to you: it’s your ears, your acoustics, your music and most importantly… it’s your taste!
Bowers & Wilkins has undoubtedly made a quality leap with the D4. Distortion is more even and lower than in the D3 line. And you can hear it. The sonic signature remains Bowers & Wilkins. But there's a point to be made: people buy Bowers because it sounds like a Bowers.
A leap in quality makes us happy. The price jump makes us less happy: the older version was around 6,500 Euro per pair with stands. For the new one, you're looking at four zeros. That's 50% more. Bowers enters the territory of the Sopra No1, Sonus Faber Electra Amator, Kudos Titan 505 and, for example, the Grimm LS1a (13,000, but it's active). It's up to you to decide what suits you.