Why do only US makers focus on time coherency?

If you were to close your eyes at a live concert, you'd be surprised at how hard it is to pinpoint the position of instruments/voices. With your eyes open, however, it's quite easy. (A lot of things are easier with your eyes open.) Good imaging at home helps to make up for the lack of visual cues.

Of course, good imaging is a function of a number of factors, including the recording and speaker-room interaction, as well as the listener's own sense of what it _should_ sound like. I'd be wary of any dogmatic claims that "X" type of speaker is the best for imaging.

To Seandtaylor99:
I've owned B&W DM604S2 for 3 years & I felt that these speakers imaged very well. I've heard many B&W speakers in DM series, N series & the now discontinued CDM series. Each time I thought that, if nothing else, the imaging was very good. Maybe your demands on imaging are far more stringent than mine??

To Dawgbyte:
Are you ever going to purchase a new set of speakers?? :-) I think that you have been posting on this forum for well over 1 year soliciting advice. Perhaps this has lead to analysis paralysis?? ;-)

Lastly, I 2nd what Bomarc has observed: We audiophiles put a lot of weight on imaging & maybe more than what is necessary 'cuz whenever I have been in a live concert, the imaging has never been pin-point especially if I bought "good seats". My criteria of a "good seat" is as close to the stage as possible. I'm sure that many others value the same. However, if the band or orchestra is so close to you, there is NO way in Hell that the imaging can be pin-point! It HAS to be diffuse as the sound just left the instruments & all the instruments across the stage just CANNOT combine that quickly to form a pin-point image. In fact, the further away I have sat (didn't get to Ticketmaster early enough to get that "good seat"!) the more pin-point the imaging has been. In fact, off lately, I have been appreciating the mid-hall presentation of music (whereas earlier I was almost always a front-row-center kind of guy).
So, maybe the Brits/Europeans are not that wrong in considering PRaT. They might be considering PRaT to give a wholeness to the music, which is very important for our resp. listening enjoyment.
Of course, IMHO. FWIW. YMMV.

Why don't you just forget about speaker design, listen to a bunch of stuff, and decide what you like? There is no best speaker design, just the best speaker for you and your room.

No, there is no such thing as a "best speaker design", but not all speakers are created equally. I think speaker design/theory/approach/methodology/materials etc. is extremely important, otherwise designers wouldn't spend the extraordinary number of hours and cost to research and develop different approaches. The sound of these design theories will vary greatly in different situations and with associated upstream equipment and even with varying types of music.

If one is going to make a sizeable investment in a speaker, then it behooves the individual to do their homework. Buyers remorse is not an experience I'm interested in becoming intimate with.