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.
I built the OB subs with three 12" drivers for each channel. Danny's design can be built with 1, 2, 3, 4, or 6 drivers per sub, and flat packed are available for all configurations. The more drivers you have, the less each driver has to work and the faster they will settle when the signal goes away.
The servo control makes them settle very quickly anyway, but with three drivers (6 for both channels), the bass is extremely fast and articulate. If you've ever heard Magneplanars, particularly larger ones, the bass has a similar quality except the GR subs go considerably deeper and are a bit more dynamic.
The bass doesn't pressurize the room quite like a sealed box sub, since you are moving air from one part of the room to the other. So musical instruments sound more natural, but movie sound effects such as explosions don't have as much of a shock wave feel. If your primary use is home theater and you like movies with exploding helicopters, I'd probably stick with more conventional sealed box powered subs, but for music, the OB servo subs can't be beat.
I would expect the OB subs to integrate much easier with the OB speakers compared to a traditional sealed box sub. It's kind of the same issue with trying to integrate subs with Maggie's. But I haven't tried so I don't know for sure. I would post your question on AudioCircle in the GR Research forum to see if anyone else has experience.
I live in Portland, OR so quite a trek from Michigan.
It took me about 50 hours to build both the NX-Oticas and subs. Probably 30 for just the NX-Oticas. Most of that was painting. Building the cabinets was very easy - probably a couple hours total. The crossovers and wiring up the drivers took about 8 hours. And cutting and installing the NoRez for speakers and subs took another few hours.
There are a couple of You Tube videos documenting how the GR Research loudspeaker flat packs (precut MDF panels you glue together and finish) are assembled. You don't need any woodshop tools except for some wood clamps (and glue, of course). The flat packs are very easy to put together, made with alignment dowels (just like IKEA furniture) and "biscuits". I love that you can finish them (or have it done for you, as in an automotive body shop for a Wilson Audio-quality paint job, or cabinet shop if you want a genuine wood veneer finish) any way you want.
Build threads are also posted on the Audiocircle GR Research Forum website. Join the fun! Once you get used to the idea, you realize it can take your hi-fi involvement to a new level, like super-charging your car's engine with a bolt-on blower kit. Ultra-high performance for the price of mass-produced mediocrity.
Danny Richie designed and has manufactured his own drivers (including the NEO3 planar-magnetic tweeter), and his cross-overs are the best in the business. Don't wait for a review of a GR Research product in Stereophile, it ain't gonna happen. But lots of speaker companies pay Danny to design the x/o's for their loudspeakers, He is a leader in the open baffle DIY market, highly respected by his peers, of which there are few. Um, does this make me a fanboy (I hate that term)?
While I have not heard Danny's speakers yet (soon) I have heard some of his work. I have a pair of Emerald Physics EP 2.7 open baffle speakers that he build new crossovers for and they sound amazing! They use much higher quality parts than the original crossovers. I have the frequency response and waterfall graphs before and after and they are quite a bit better that stock. In fact I was told by Danny and one of EP's designers that they are likely the best sounding pair of EP speakers on the planet.
That said I am just starting to build Danny's latest speaker design, the new NX Studio monitor kit. Just received the kit and all the MDF, cherry veneer and grill cloth and stuff over last week and will start the build this weekend. Very excited about this. See it here: https://www.audiocircle.com/index.php?topic=160647.0
Also see this as to why you can build better speakers than you can buy in most cases: https://www.youtube.com/watch?v=7yozUh8xBfk&list=PLUFNGRKZZWXzCt2Syx4yjR4Oy7V-uiePB&index=19
I recommend subscribing to that channel and watching all the videos. Very educational.
I guess it depends on what you are looking for. I find the bass to sound very natural sounding and extremely dynamic, as if you were listening to acoustic instruments in the room. You can still feel the bass, but it's probably a bit closer to what you'd get from a high quality open back headphone (e.g. more sound than pressure).
Hope that helps.
There is a pretty noticeable difference between the Ottica's and Xtreme's and it's not just with the WAF as they stand 86 inches!! There is an added fullness to the sound from the additional 8 drivers that seems to be greater than the sum of 4 extra drivers, the fact that they barely break a sweat during large musical passages really helps define the inner detail that can sometimes get lost during increased spl's. There is also a deeper sound stage that also comes with having more drivers that can be quite addictive if you have the room to support them and in this regard the Ottica's are far easier to place within your average room. I own the first pair built, and my partner Jay and I build almost all of the flat packs sold, I run mine with a 4 stack of 12 inch GR subs and the combination will absolutely shock you with well recorded music. To give you another perspective, and i'm trying not to be too biased, I recently attended the Toronto Audio show, which I thought was excellent and the speakers that I felt had the closest signature to the Xtreme's, meaning with scale and size of presentation were from Grandinote, they were OBish line arrays and I believe that they cost 60K.
Hope that also helps,