Only the ZxR uses Nichicon capacitors. The Zx is the same card as the Z, it just has the module thing included. The specs are exactly the same. If different components were used for the Zx, the specs would not be the same. There is no mention at all on Creative's site of the microphone being included with the Zx. If you look at what is included with the Zx, it's not there.
Ah, you don't understand, the beamforming microphone array is built into the audio control module
And a creative support guy on another forum confirmed that the Zx and Zxr have the Nichicon FG caps. Only the Z hasn't.
The type of CAPS don't make any difference to the audio quality that's why the specs are the same, I suppose,maybe, the FG caps do a better job of smoothing out voltage spikes.
While the SNR ratio and specs are the same, the Zx's external Dac could be driving all 5.1 channels. The external dac on the Z is only driving the front channels the integrated dac on the core3d is driving the others. The rear channels on the Z only get a 103 Db SNR measurement in RMAA. The front channels get the full 116 Db. The Zx might be able to get 116 Db for all channels.
But most of that is just speculation, apart from the FG caps and the microphone. It will be interesting to see what the actual differences are when the cards are finally released.