Triangle Antal Es and Thiel 2.4's

Besides reading the spex on both of these products and if money was no object which is the SMARTER buy? Buy A because of the name they built for themselves or buy B because they have been around for awhile and have a hugh marketing budget?
The smarter buy is always the one that satisfies you more. That's money well spent.
The one that satisfies you more will be the one you can drive well and position well in yr room.
In yr stated choice the marketing budget is a secondary consideration.
Triangle is the one with the huge marketing budget, right?
I haven't heard the Triangles, but I recently bought the 2.4s which I use in a HT setup driven by Audio Refinement Pre2 DSP and Multi-5 amp. I was able to arrange a home audition before I bought them.

Break-in took about 50 hours and I think these speakers sound fantastic. They've been reviewed in a few places; I'm not gonna repeat a review here, but I certainly agree with the published reviews and impressions. If you send 'em a good quality signal, they'll really sing for you.

Gregm is right; "smarter" is what satisfies you. But I wouldn't be concerned about marketing budgets, especially with a company like Thiel. Jim Thiel has had an excellent reputation in the industry for many years.

Good luck with your decision.
Triangles are not for everyone. They are too accurate for some and too forward for others. I personally like their sound a lot and am considering getting one of their big models from the Stratos line. I have a pair of Comete ES now and they have phenomenal detail, resolution and clarity - better than my 4.2x more expensive JM Labs. However the JM Labs are better at overall refinement and soundstage size but that may be largely due to their much larger cabinet sizes.

I am quite familiar with a number of Thiels (friends owned them) and in a way, they have a similar sonic signature as the Triangles - probably the closest I can think of actually. Personally, I would go with the Triangles but it will depend on the rest of your gear, your room and your tastes. Good luck! Arthur
2.4's are not for everyone either. I bought a pair new after auditioning 2.3's in my home environment. I ran them with all the 'right stuff' (Pass X250, X2.5 pre, 306/200 CDP, Cardas Gold Cross, etc) & they were fully broken in. Problem was I couldn't listen to 80% of my CD collection. They rendered the music unlistenable. I must admit the 20% that was well recorded/produced was really good. by all means audition with music you listen to.
Thiel's are much harder to drive.

I own the Triangle Celius and am very pleased. i have heard the Thiel's several times and never liked them (however the rooms and set up were aweful)

The comments on the Triangles being bright is correct. I used an RTA to set up my system and can see the tip up on the graph. As such assuming one's hearing doesn't roll off (which is what I am counting on with older age) one can use a tube amp, avoid direct toe in or even put a 1 or 2 ohm resistor in series with the tweater until old age sets in. I run them on my 4 ohm taps which are a bit rolled off and don't point them directly at me. I love the speakers
From Stereophile review of Triangle Magellan Concerto:

"The impedance magnitude remains between 2 and 4 ohms over almost the entire audioband, and there is an amplifier-punishing combination of 3.7 ohms and a 44° capacitive phase angle at 78Hz. An amplifier capable of hefty current delivery is going to be a must with this loudspeaker.

In the time domain, the Magellan's step response indicates that all the drive-units are connected with the same positive acoustic polarity, the step of each blending smoothly into that of the next lower in frequency—but the ringing from the horn-loaded tweeter is very much in evidence.

Some things the Triangle Magellan Concerto does very well—the high sensitivity and dynamic range, the well-controlled treble dispersion, the optimally aligned bass tuning, the overall in-room response flatness. But its impedance will make significant demands for current on the partnering amplifier, and I don't like to see the resonant energy in the presence region and the top octave."

And from Stereophile review of the Thiel 2.4

"...despite Wes Phillips' conjecture that this speaker is not too hard to drive, its impedance plot (fig.1) indicates that the CS2.4 demands a lot of current from amplifiers. Not only does its impedance drop to 2.73 ohms at 600Hz, but it stays significantly below 4 ohms from 100Hz to 50kHz, and there is a difficult combination of 4.5 ohms magnitude and –45° electrical phase angle at 80Hz. Thiel CS2.4 owners should make sure they have a good 4 ohm–rated amplifier to drive this speaker.

The CS2.4's step response (fig.6) has almost a perfect right-triangle shape with just a small amount of leading-edge overshoot apparent, this correlating with the shelved-up top octaves seen in the frequency response.

Overall, the Thiel CS2.4 offers pretty good measured performance, its few idiosyncrasies resulting from the designer's use of a first-order crossover between the woofer and midrange unit."

Both require good amps to drive effectively. The accuracy in the time domain means that harmonic content is better preserved with the Thiel.
The Thiel will exceed at "timbre" over the Triangle.
If micro dynamics is your thing, then, the Thiel is your speaker.
I know this because I bought a pair. Happy Listening!