This is a very misunderstood lens.
I think that because it used to come as a kit lens, people assume it's going to be basically a glorified end cap. This is to do this product a major injustice.
The 18-70 range is just ideal for 90% of what I do with it. You'd maybe expect some distortion, but I can't see any once you're over about 28mm.
It's as sharp as any other mid-priced zoom (to my eyes anyway - although for ultimate quality you'd do better to ditch zooms altogether and go for the outstanding Nikon 50mm F1.8D AF Nikkor Lens
instead, which will blow it away technically)
Any slight tendency to barrel distortion of vertical lines can be corrected on the D90 with a couple of clicks of the inbuilt software anyway. Maybe not perfectly, but it's plenty good enough for 98% of people that will buy and use this lens, including me. For the remaining 2% of people who would find this unacceptable there's always the "perspective control" lenses or good old computer software. If you really want to spend the money. Personally I don't. I'm more than happy with this lens as it is.
Maybe it's not the fastest kid on the block on paper, having a max aperture of only F/3.5, but these days who really cares? On a digital body (Like this lens is designed for) the camera will just ramp up the ISO to deal with the available light, so lens speed is not crucial as it was in the days of film.
Personally, even when I use my excellent 50mm F/1.8D I very rarely use the lens wide open as the DOF is just so shallow that accurate focus becomes a problem. For portraits and nice blurred backgrounds I almost always selected F/2.8 or 3.5 anyway, and this lens does that fine.
On the other hand, even at maximum zoom its aperture is still F/4.5. This might not sound like a big deal over an F/5.6 of most super-zooms, but it's 1 extra stop. That's something that marks this lens out as a good one compared to the competition.
I know that the current trend is towards "Super-Zooms" that can go from 18-250 or whatever, but I would prefer to have this first. Then IF I need it, I can take my excellent Nikon 55-200VR DX Zoom (new for about £150) which is an excellent choice of zoom.
Those big "Super-Zooms" are way bigger and heavier than this, there's lots of sections that telescope out and in, and more to go wrong because there is more inside them. How often do I ever need 250 or 300mm anyway? Only for motor races, and if I'm going to an event like that I can easily take the 55-200VR zoom along. For general wandering-about use this lens is absolutely ideal. Compact, fast (Both optically and mechanically) and good quality in terms of build and results.
It has a metal mount, unlike some dearer Nikon lenses, and the AF speed is incredibly fast and quiet thanks to its Silent Wave motor. No VR, but I've not missed it on a lens this short. I don't recall ever taking a blurry shot with this anyway (Unless trying to do something really dumb like hand-holding a 1/15th exposure in the dark, and even then it could be okay 50% of the time)
I bought mine used for £90 and I consider that a real bargain. Even at full price I'd say it was a good buy but get yourself a used one if you can. There are so many that have been traded in by people who got them with their kit and didn't realise just how good they were that they're cheap and plentiful. Mine was as new for half the price, so why pay top dollar?
Heartily recommended. Four stars overall, but 5 stars for the value for money.