Searching for the most "accurate" speaker (below 15K)

If you mean accurate as in a speaker that sounds like the real thing then I think the Yamaha NS5000 sets a new reference point.Especially in the midrange.Piano ,voices,strings or anything natural are all the most convincing I have heard from any speaker.And by a fair margin.
Not only are they extremely detailed  but they are also very musical and organic sounding.Imaging is also right up there with the best I have heard.
I used to love the Magico S5 but when I went directly from them to the Yamahas I realised the Yamahas sounded real whereas the Magico just sounded like a speaker-albeit a very good one.

@prof , Thanks for sharing your experience. I know the Anthem electronics and I see them as "good value" but a long way behind the refinement of the absolute best solid state amplifiers (the newest Nagra generation, Constellation Audio, Soulution, CH Precision, Dartzeel or Pass Labs). So I think your opinion could be somehow different had you listened to them with different electronics. But I also agree with your statement "I’ve found there is only so far one can go with peripherals like amps etc in terms of altering the sound of a speaker. "

So, "vive la différence" ... the world would be quite boring if we all agreed :) Enjoy your Thiel’s!

@jtgofish : i heard a lot of good things about the new Yamaha 5000 ... but they're not available in my country :/

If you really want to hear the flatest and most phase linear speakers ever(im an sound engineer and i dont bs)then try to source&audition a pair of MeyerSound HD1 midfield studio monitors(no longer in production)....but you probably wont like them :)
But I do
They used to cost in the region of 3000 each
Good luck

addendum to previous comment about HD1's...they are self powered