What's the current thinking - are prime lenses still going to give you superior image quality than zooms? Or, has the science of lens design and manufacture advanced to where zooms can equal the quality of primes? Even if zooms are not quite as good as primes, does the ability to precisely frame the shot, and therefore not have to crop any precious pixels, balance things out in the final print?
I am interested specifically in Nikkors, if that makes any difference.
Peter
As usual, "it depends".
Modern high end zooms are very good indeed, but they still can't quite match the resolution/contrast of an equally good prime lens. This quality difference will only be evident if you're using excellent technique and printing to large sizes—low ISO, tripod mounted, mirror lockup, meticulous care in focusing and exposure etc; otherwise deficiencies in technique will obscure the distinction. Backlit subjects will be easier to shoot with a prime lens since flare is a lot less problematic.
I think you've hit the nail on the head when it comes to the real world trade-off. With zooms you can frame precisely and avoid wasting pixels, particularly important for landscape images where composition often dictates a very specific camera location and perspective. A prime lens may give you better absolute resolution, but if you have to crop by 15% to get the framing you want, it may be a net wash.
For what it's worth, for landscapes I use zooms almost exclusively on a Canon Eos-1Ds III. I'm aware that the mediocre optical quality of Canon's wider zooms is the weakest link in the image quality chain, but down to about 24 mm or so they're pretty good, and the 70 - 200 f:2.8 IS is a gem. If I need a wider perspective with good resolution I start stitching frames. Nikon's 14 - 24 mm appears to be optically much better than any of Canon's wide zooms, so that might make the decision easier. You will be able to eke out a bit more resolution with prime lenses, but the trade off in lens swapping and the need for cropping isn't worth it to me, and I'm very happy with image quality of prints up to 24x76" panos. Others may of course see it differently.
I do routinely use prime lenses for people pictures—not for the resolution, but for the beautiful soft
bokeh and the wide aperture for indoor natural light shots.