Is the 18-200 really sharp at F8 or does it still drop in sharpness?

[The Man from Mandrem]

Have been looking at a zoom to complete my lens kit.

Requirements:
Light weight
Very sharp at F8 if not wider
Decent AF-S (As fast as 35/1.8 on my D7000)
Covers 18-70 (I used to use on film what is 20-27mm on DX ALOT but currently don't have a lens for it)
VR (Ideally VR2)
Not TOO plasticky
$600 or so (at least used)
Good bokeh at 20-27mm preferred but not needed

I currently find myself making too many lens changes going WA-UWA-Tele and don't want to get another/different UWA.

16-85 and 18-200 I am mainly looking at (read all I can find). Would like max zoom range that remains very sharp (at least at F8) with good AFS and VR. The question really is how the 18-200 performs at F8. It's hard to understand synthesizing the reviews.

I have following lenses: T116, T535, T270II, AI180/2.8, AIS105/2.5, AIS55/2.8m, 35/1.8DX, 50/1.8D; and converter: TC200. I will get 70-300ED VR to replace a unit I destroyed. I will use the zoom + 1-2 of these on any major trip, zoom alone or 1 of these alone on any minor outing.

[Dman51]

Just bought the Tamron 18-270 pzd and have to say for it's range its very compact and smallest in its class. It has a silent autofocus thanks to the new pizeo drive technology. Reaches an extra 70mm over the Nikon has a very quick AF-S for a telephoto of this range and a great VR called (DC) from Tamron. I see good sharpness all around some soft spots in the mid range but I noticed that with the Nikon 18-200 as well sort of comes with the nature of the territory. $650 new but you can find it cheaper if you google it.

[Franglais]

I find that the Nikon 18-200 is sharpest from f8-f13.5. I use it a lot in the studio, and that's what I get from the flashes. It's sharp even out to 200mm.

The times I've noticed the 18-200 being less sharp have been when I'm zoomed out to almost 200mm, I forget that this is a pretty long focal length and I don't steady the camera enough. VR can't correct a really clumsy operator.

I try to avoid the widest apertures but I can't say I've noticed a case where the 18-200 isn't sharp. ompare it side-by-side with the 16-85 and if you look very closely it's just a little less sharp but not enough to matter

The autofocus is not as fast and sure as the 35mm, especially at longer focal lengths (f5.6 lens instead of f1.8 lens = 8 times less light to work with..). Not the ideal lens to do sports or an air display but still usable.

You will hate the look and feel of the 18-200 when the front element is cranked out to 200mm. But it works. You want a solid lens then go for the 16-85.