The latest generation of B&W speakers all seem to have the familiar 5-dB or so rise centered around 10KHz. I borrowed a pair of the 600 series' big brothers, the 706 S2. According to measurements I've seen, they share the rising top end of the 607s. I listen to classical music, which means a lot of violins, which in turn means listening to a lot of strident recordings of violins. I am very sensitive to this kind of shrillness (it's my pet peeve), and to my ears, the 706s presented a very subtle, very realistic portrayal of violins.
The speakers are a bit recessed in the brightness region, below 10KHz, but very airy and feathery around 10KHz and above. This is the sound I hear in the concert hall: a delightful, breathy, velvety sheen that hovers above the fundamental sounds. I didn't find the 706s to be shrill or strident on the music I love most. In reality, they presented a very realistic representation of real instruments. And they may be in my future!