The NX-Oticas are a pretty amazing value if you're willing to put in a little time to put them together. They produce a deep spacious sound stage with excellent clarity and detail and fantastic dynamics. They are very easy to drive with over 93db/watt efficiency.
Downsides - they need to be several feet into the room to sound their best (mine are set up with the front of the battle about 6.5 ft from the front wall); they really need subs to be truly full range (they go down to 45 or 50 hz on their own, but matched with stereo OB servo subs, they are incredible); and, you have to put them together and finish them yourself (or pay someone to do it)
I really enjoyed the process of building them and am thrilled with the sound. I think these are the most satisfying speakers I've ever owned after 45 years in this hobby (and over a dozen speaker systems, many costing several times the cost of the NX-Oticas with subs).
If you've got high enough ceilings, I expect the NX-Extremes would be a nice step up, From what I've heard, they have a bit more punch in the mid bass and a little more height to the imaging. My ceiling is just under 8' which I don't think is high enough to allow these speakers to sound their best.
