Sorry for the late reply - I've been away at the Focus on Imaging show for a coupl of days
Yes, I'm quite serious that there is no generic "FX Effect".
But... I think my posts on this subject may have been misinterpreted, either accidentally or deliberately. I will try once more to explain where I'm coming from.
I bought a D700 because it offered better noise performance than any other Nikon camera that I could afford. Its 1+ stop advantage over the D300 at high ISO's allows me to get more usable (i.e. saleable) shots of stage performances. The D700 is a remarkable camera, with an excellent balance of specification and performance that suits much of my work to a "T". Note that the D300 does a great job too, and at lower ISO settings I still don't see too much difference between them.
However, the fact that the D700 is an FX camera was (and is) is not relevant to my purchase decision. Because it's FX, I have had to alter which focal lengths I use to get the desired angles of view, and I still prefer the greater effective DoF of the D300 (for the same aperture and framing). If the "D400" (or whatever the next high-end DX camera turns out to be) can offer D700 levels of noise at ISO 6400 or so, it will be - FOR ME - an even better option. At that point, I could be shooting a "D400" for the longer shots and the D700 for wider full-stage views. With further improvements in technology, I might well switch fully back to DX.
I hope I've countered any impression that I don't rate the D700 very highly, but equally, I must emphasise one last time that the big improvements which the D700 offers over earlier DX cameras like the D200 and D2X are not all down to the format. An equally (arguably, more) important factor is that the D700 employs a newer generation of sensor and firmware. And that's what I mean by there being no "FX Effect". The D700 is great, but not (or not only) because it is FX