The big Klipsch's will never fully take on the character of a polite British loudspeaker. But, who want them to?
As stated in this forum, horns are unforgiving of "mid-fi" and will confidently reveal the warts promenent in lesser systems. For the adventurous, many of the modification listed here pay big sonic dividends. In my decades of providing performance upgrades to Klipsch speakers (RB51s -> K'Horns) it is our view that improving the integrity of the signal path yields better bang-for-the-buck gains than component upgrades. i.e. Use the same (or, better) cabing you use from amp to speaker for all internal cabling in the speaker. Eliminate spades, lugs, terminal strips, etc. -- siliver solder every connection.
I find the great irony of high efficiency horn speakers is just how good they sound at LOW volume levels. Just above the threshold of hearing they deliver: dynamic impact, detail, microdynamics, bandwidth, and spacial information. Nothing else comes close.