Rick - Great review and you have really gotten my interest in the RCF's, as had others.
But, I am really interested in if you have had time to use the NX12 and the Atomic in a stereo configuration. For some reason that approach has hit a nerve with me and I am most interested in anyone's views who has tried that setup. GAS has struck again; and as always it is great!
I did not try them in stereo, as I had my Axe II set up for a single speaker (my normal rig). But I did connect them on an A/B/Both switch box (Taylor brand, if interested) when I was comparing them, and it gave me a chance to combine them with one button push. They actually sound nice together, complimentary even. The Atomic is a decent (though somewhat, well, flat in comparison) sounding speaker, and has more apparent high end. The RCF has much more detail and a much punchier low and mid production, so combined there is a little more upper high end audible. Because they do sound so different they are definitely usable together, however... (see note below)
i honestly think you'll get a more balanced sound using two nx12's.
i have experience of the atomics (pair of powered wedges in stereo) and the nx10's (pair in stereo)
i haven't run both together, but the 12's have such a transparent image, it would be a shame to pair it with something that pales in comparison. and they sound completely different...
I tend to agree with Simeon. As the RCF can be EQed to produce more highs if you want them, and the detail of the speaker is so much better, I would think a stereo pair of them (10 or 12, both highly regarded from what I have read) EQed to your tastes would be the best of everything. With The RCF being roughly 2/3 the size (I need to go ahead and compute the volume to get more exact on that), two of them will significantly reduce your setup size, with a real and clearly audible gain in performance to boot.
But... (always one of them)
I don't have a second one! So, if I need more air movement or want to go purely stereo on a preset, I would not be at all bashful about firing up the Atomic with the RCF. The Atomic is still a good sounding speaker and doesn't get in the way (tone-wise) of the RCF, so sometimes you "dance with the girl ya' got!" Until I get this RCF paid for and can afford a second, this will be my plan when two speakers are demanded.