Scoring on Used Thiels here

both the 2.3's and 2.4's drop below 3 Ohms.

From Stereophile's CS2.3 measurements:

The Thiel featured above-average sensitivity, at an estimated 90.5dB(B)/2.83V/m. However, like all Jim Thiel designs, it is quite a demanding load for an amplifier to drive. Its plot of impedance magnitude and phase (fig.1) reveals it to remain below 5 ohms throughout the midrange and treble, with a dip to 2 ohms at 450Hz. Note also the combination of low impedance and high capacitive phase angle in the upper bass—wimpy amplifiers stay home.

 

unsound,

I was big on Dunlavy when they were popular, heard many models, including auditioning some as possible purchases.   The Aletha model (unfortunately not many made as Dunlavy folded not long after introduction) was really something.  It produced one of the most realistic sound I'd heard at that point.   But as you know Dunlavy speakers were always really big, even their "decor-sized" models like the Aletha.
And Dunlavy was a bit more head-in-the-vice in terms of optimizing listener position, Thiels with the coaxial drivers more forgiving.

^Agreed.

^More restricted, but not "head-in-the-vice" restricted like some beamy ESL's. I suspect it might be due at least in part to Dunlavy's preferred angled placement. Perhaps, with a higher and denser soundstage than the Thiel's.

The MBL omnis are peerless for disappearing and creating a 3 dimensional sonic image. Absolutely spooky, and ultimately the most realistic presentation within their frequency range

I've only heard MBLs once, at RMAF. They sounded good to my ears but nothing special. The room set-up was weird, tho', with the speakers along the long wall. Probably not optimal placement.