When we were at the showroom in Atlanta one of Julian's assistants A/B's the Time Windows against a pair of similarly priced Magnepans. The Magnepans sounded dull in the highs and my 3 friends and I were all impressed more by the Time Windows although I do recall the Magnepans could throw up a stage quite well even in those days. So maybe my amplification and preamplification just weren't good enough. I sold them to a friend and he's kept them for years and is still happy with his purchase.
I've moved on to home built Linkwitz Orion speakers which are in another league altogether.
I'm pretty sure one of the reasons I wasn't taken with the Time Windows is that I love to hear a 2 channel system create a 3D illusion of a soundstage and still do. I know now from experience that a preamp and amp can prevent a speaker from throwing that soundstage. But the LS3/5as can and do and so do the Magnepans -each in its own way. The midrange of the LS3/5a was also much more neutral than the Time Windows I'd love to hear the Time Windows with some of the newer better amplifiers that are out there as my opinion seems quite out of sync with the rest of this group and I sure as heck might change my opinion if I were to hear them again. I do still recall how we four college students all agreed that the Time Windows beat the pants off the Magnepans.
Incidentally, I don't recall the high end as being dull. In fact, I wasn't taken with that metal dome tweeter at all.