Why did you choose a horn based loudspeaker?

I did NOT choose horns. They all sounded unrealistic to me untill I heard Avangard ones at dealer each in separate room. Uno and Duo are hybrid horn with dynamic subwoofer and Trio is all horn. Fast and open sound with close to studio-mastering precision and clarity. Their looks are also subject for the exitement. Taken all so much of positives, nevertheless, I got tired of listening after 15...20min. During next couple of hours after listening I had ringing sound in my ears.
Obviously horns are easy to drive with low-powered tube amp and by all audiophile standards these are the most transparent and pure.

Also worth mentioning that high sensitivity speakers like most horns are extremely sensitive to EVERYTHING, not just the music. That includes noise, distortion, or any kind of sonic abnormality. So getting things just right upstream is more critical than ever. Not always easy to accomplish or maintain over time. That's just one reason why many horn demos might underwhelm or cause fatigue faster.

But, if you get it all right....then you have something. I have heard some really good, large expensive horn systems and enjoyed them for extended demos, but have never lived with any to-date for the long term, whichis what matters in the end.

I like to listen to music at lower volume levels and nothing really comes close to a horn system in terms of delivering dynamics (liveliness), musical detail and a complete harmonic palette like horns at lower volume levels. Horns can deliver astonishing detail while still sounding relaxed (not edgy and strident). Higher efficiency of some horn systems also mean that the best sounding amps can be utilized--low-powered tube gear--which can deliver the most natural sound (great transient response without the artificial "edge" of solid state, "dense" and weighty sound without being sluggish).

The price that one has to pay is the presence of some obvious tonal coloration. Some horn/compression drivers are pretty mild in that regard, such as vintage Western Electric and International Projection Company gear, and certain modern horn systems such as Edgarhorns, Goto/ALE and Avantgardes, but, horn sound is still present in some form. The other price one has to pay is...well...the PRICE (good horns and compression drivers are not cheap).

Like most audiophiles, I have owned a number of different speakers large and small, including Khorns. I currently use horns, simply because they are the all around most natural sounding speakers I have ever owned, but then, I am not in the big leagues, and have never owned a speaker worth more than 12k.
I agree with Mapman though that I could also feel perfectly content with other speakers. (yes, including Ohms)
It is true that most horn speakers have wide dynamics, but many dynamic speakers are very dynamic as well. The Coincident Total Eclipse is one that I really liked in that regard, and should have bought. Although I really liked the Spendors that I owned, dynamics were a weak point.
In my current speakers, the treble and midrange is handled by a single horn, which has a 12" driver above and below it.
The one horn covers so much of the audible range, and to my ears, the transition to the lower bass is pretty seamless.
In the end, I would say wider dynamics are a strong point with horns in general, and of course, some are shouty and cause fatigue to some listeners. If mine were, it would annoy me as well.

Had a couple pair of Klipsch Heresy's back in the day; one home audio pair and one pair of stage monitors. They were hyper-efficient and had nice dynamic range for the relatively low-powered amps I had available (Hafler DH200, DH220 and a Dunlap-Clarke Dreadnought 500). That made them very budget-friendly for a student and garage sound engineer of limited means. However and just like Czarivey, I came to find them overly fatiguing during home use at low volumes. They were especially sensitive to IM distortion. Never had the chance to try them with a good tube amp like the MC275, so I can't say if I might have stuck with the horn-loaded configuration. I them moved into the Rogers I'm still using today and have been more than satisfied with them for over 30 years. Hope this is useful for you!