Please Recommend Highly Efficient Floor Standing Non-Horn Speaker Suggestions

Highly efficient its horns that’s it. And not mentioning what type of tube amp is not helping since tube amps are from 1/2 watt -200 watts. Good luck

Highly efficient its horns that’s it. 

That's it? That's the only option? That's the best option?

Bit of a hit and run, friend. What is your reasoning?

Consider Voxativ, which are very efficient and single driver. I’ve owned modded Klipsch Belles and Zu’s. All three are great, but very different listening experiences with SET. Because I like speed and precision for jazz vocals (e.g., Jacintha), Vox is it for me with their single drivers. Good luck

we might need a definition of horn here.  Are we talking about a system with a midrange compression driver, or do all of the drivers have to be horn-loaded?  Does a woofer with a front waveguide qualify as a horn system?  What about systems that have a quarter wave backloaded horn structure?

I like a lot of systems with old school vintage midrange compression drivers--Western Electric, International Projector Company, YL, etc. drivers, and a small handful of modern replica drivers (mainly G.I.P. Laboratories replicas).  These systems may or may not have compression tweeters and woofers can be of all sorts and in all kinds of enclosures--open baffle, sealed enclosures, infinite baffle (particularly like Onken versions), or horn-loaded bass cabinets.

But, I don't think that good high efficiency systems necessarily have to use compression drivers.  I've heard a number of systems using full-range dynamic drivers in either single-way or multi-way systems that are terrific sounding.  Whether some of these are also categorically horn systems depend on how one defines horn (e.g., Charney single-way systems use quarter wave back loaded horn cabinets).  

The fact that OP asked about non-horn systems suggest a dislike for "horns."  I suspect that this is the result of hearing some more common horn systems that were not to that person's liking.  This is a bit regrettable because there is a vast array of horn systems with quite different sounds, including many that don't have a peaky midrange or tendency toward a nasal coloration that one often hears in more common horn systems.  

So.... I have interviewed the Ascend Acoustics sierra towers in my own home against another speaker system about 3 years ago. The Sierra Towers gor sent back but they were picked as just one of 2 systems I was interested in. If your budget is 3 to 5k, I would absolutely go that route. They are wonderful speakers but you will need a good subwoofer (s) to go with them as the base is the weak spot against others; and don't let the Ascend fan boys impress you with all of their graphs and measurements and all on that last point. They are a loyal bunch and anyone who says anything negative about this $2700 speaker is a heretic. So again, this is a good choice.

That being said, I have since moved out of this price range and into a completely different world. And I do mean..... wow, huge difference. At 96DB sensitivity my Legacy focus XD speakers are unbelievable. (no subs needed for sure). The ribbon tweeters in this system are mind blowing. I think you would be happy also with the SE version (without built in woofer amplification) and the Legacy signature (the little sister to this speaker that I have also spent some time with, just before stepping up to the XD..... just because I could). As to the rest mentioned in this thread. I have heard none of them so check them out also. Good luck