I don't feel the grey-mesh V4's lack in resolution and detail retrieval. Of all the Magnum drivers I own I consider them the best. Although I have to add that I do not own any of the all-black V4's. The first-batch V4's, however, the ones with the grey ring and black mesh, seem to be slightly recessed in the higher frequencies, though. The V3.5's are noticeably brighter than any of the V4's, a tad shoutier in the upper mids and have less bass body and extension.
I can confirm what thelostMid has stated about the effect of cup materials on sound. Wood species, cup length and geometry all do have an effect, to my ears the effects are not really that dramatic, though. Maybe my ears are not trained as well as thelostMid's. If I only owned a set of drivers in wood and I liked what I heard, I would not start worrying and think of finding out if there was more to it. You can only detect these slight variations if you own more sets of drivers, more wood and alu cups and when you carefully and thoroughly A/B your setups.
There also is driver variation between batches. But isn't that what people are finding out about other manufacturers as well? Just have a look at Tyll's article on innerfidelity on LCD-3 variations. And people have often mentioned that no RS1 sounded really the same as another one. It is only when you A/B several drivers of the same manufacturer and series that you will notice the differences.