Thanks for the compliments.
@ryno - I've owned three different Maggies over the years - MG1s in the late 70's, Tympani IVs in the mid-80's, and MG3.6Rs a few years ago. What I loved about the Magnepans is the open-airy soundstage and the total lack of boxiness in the sound. The ribbon tweeters have an incredible delicacy to the sound, but don't always integrate perfectly with the planar-magnetic drivers. The biggest negatives of the Maggies were lack of dynamics (everything sounds a little soft which is great for vocals, sax, etc., but leaves me wanting on percussion, guitar, piano, etc.), limited low bass, and lack of imaging precision (the Maggies portrayed a deep and wide sound stage, but it was more difficult to pin point the position of musicians/instruments). I don't have any experience with the MG-20 or MG-30, which likely address some of these weaknesses.
The NX-Oticas have a similar deep, wide, airy soundstage, but have somewhat better image specificity and are much more dynamic. They can play loud completely effortlessly, but still sound well balanced at lower listening levels. With the OB subs, they totally trounce the Maggies I've owned below about 50Hz. Of course, you could always add GR's OB subs to the Magnepans and they would probably integrate very well as both are dipoles.
The NX-Oticas have more clarity and detail than I remember getting from any of my Maggies. I always used the stock crossovers on the Maggies, and I suspect part or all of this difference is in the quality of the crossover components. My NX-Oticas include the upgrades to the caps and inductors that Danny offers. I suspect there is even more room for improvement here by replacing some of the Sonicaps with even better options, but this would add considerable expense.
I think female vocals sounded a bit smoother on the MG3.6Rs, but not as detailed. On the NX-Oticas, I can hear details such as inhalation and lip smacks much more clearly on well recorded music. But male vocals are much more authoritative on the NX-Oticas. You can hear more of the guttural sounds you'd expect from a deep male voice.
I think the NX-Otica midrange drivers are probably their weak spot. Not that they are bad, but I don't think the integration with the NEO3 tweeter is as good as it could be with, say, the NEO10 drivers. Female vocals are handled by both the NEO3 tweeter and the 6" midrange drivers and the combination of (or transition between) these drivers can add a bit of roughness to the sound. This is probably exacerbated by the high level of detail and clarity that these speakers portray, and is more noticeable on really good recordings. This is not in the least a serious flaw, but it's the one area where the NX-Oticas and OB subs are not obviously better than any other speaker I've owned. On a side note - I'm dying to hear the Line Force since I think this would up the ante in all respects and, based on how good the NEO3 is, would almost certainly significantly improve on the upper midrange.
The Maggies are a lot harder to drive than the NX-Oticas. No matter how loud I play the NX-Oticas, my Parasound JC-5 amp seems to be loafing along and is no warmer than idle. From what I've heard, the Oticas can be driven easily with 10-30 watts. The Maggies require some serious power and current to really open up. I used a Levinson ML-3 with my Tympani IVs and a Krell FPB-300 with my MG3.6Rs.
Hope this helps answer your question.