Well, I have extensive experience (and issued a review on some other newsgroup). To me it is 1) a joy to use, 2) a lesser, modern 50/1.2, 3) not properly named.
About 1) : manufacturing quality is superb, handling too. I guess you noticed... hard to resist.
About 2) : it has some kind of dual personality (like the 50/1.2) but to a lesser extent: "dreamy" look wide open (less so than the 50/1.2), very sharp from f/2.8 (I think the 50/1.2 is better at f/2.0). On the other hand, images from f/2.8 are probably cleaner with the Voigtländer (less CA, less distortion, less flare)
About 3) : night shots are very good from f/2.8. But below... Strong "glow" and coma at f/1.4 make night shots unpalatable, unless you want special effects (that's probably the price to be paid for getting dreamy shots). Better avoid point light sources in the frame, in which case you will get rewarded by reasonably sharp pictures with good color and decent fringing. Otherwise, from f/2.0, it is +/- acceptable. I would rather use the 50/1.8G under such circumstances and such aperture. I fail to understand why some reviewers compared it favourably to the Noct Nikkor in that respect (well, the published pics avoided point light sources... but the evaluation seems biased because of this).
Bottom line : a very good allrounder, also providing close focus (about 1:5) if you are not too picky with sharpness at close distance. I use it a lot on the Df and guess it is, similarly, a very sensible choice on the D700. And at 200€ for a mint used copy, it is a bargain compared to the 50/1.2.
By the way I do not see the case for a "larger use" than the 50/1.2. To me, these are lenses with somewhat different styles, starting of course with the FL, but very similar "use cases". The 50/1.2 is also not very convincing at night due to coma - although stopping down is often a viable option with the D700, and even more often with the Df.
You may also be interested by the 40/2, an extremely useful lens, the IQ of which is at least as good, while obviously belonging to the same family. Conversely, I might become tempted by the 90/3.5
