I have always liked this lens. But, for what it's worth. This is what Ken Rockwell says about it.
The Nikon 18-300mm VR can replace the combination of 18-55mm VR and 55-300mm VR lenses in one lens.

This one-lens 18-300mm VR solution weighs as much as both other lenses combined, but in exchange for not needing to change lenses between ranges, costs twice as much as the pair.

Don't use this 18-300 on FX or 35mm cameras. It will never fill the frame on 35mm, and you'll only be using the small central area of the FX frame and viewfinder. For FX and 35mm, use the 28-300 VR.

For DX cameras, this lens is an easy recommendation. There is nothing on Earth like this lens. Nothing else covers this huge range with VR and instant manual-focus override. Mud brands like Tamron usually offer cheap copies, sometimes with even broader zoom ranges, but they usually lack full-time manual focus override or good VR, and certainly lack mechanical quality and often lack future compatibility with new Nikon cameras.

This Nikon 18-300mm VR is a big, competent lens. I prefer the smaller 18-200 VR, but if you really need 300mm instead of 200mm, then this 18-300mm VR is your lens. See Nikon 18-200 vs. 28-300 vs. 18-300 for more details.

I prefer a smaller lens over having to carry a bigger lens all the time just for the few times I need 300mm. Most people will jump at the chance to get out to 300mm with a twist of the wrist. Personally, carrying a lens this big for what are supposed to small DX cameras seems silly to me, but most people are going to prefer this lens. Just be careful: what seems not too heavy when first opening your box from Adorama gets a lot heavier after carrying it around your neck all day.

All: looking for some good advice concerning the Nikon 18-300mm 3.5-5.6 VR lens. I have kit lenses for my d5xxx series cameras which include 18-55, 55-200, and 55-300, all VR AF-S. Get mixed reviews from DPReview concerning warping @ 18mm & vignetting @ or near 300mm. Used price through CC 499.99. Please let me know what you think. Depending on UHH’s thoughts I may need to cancel my order and stick with the lenses I already have. My only reason for looking at the 18-300 was convenience. I know I’ll get some good info from you’all. Need to know as soon as possible. Thanks.

whatdat! Did you misspeak when you stated you were "getting rid of your Tamron 18-270 AF with no autofocus?" What did you mean by this? The older version has "VC" or vibration control while the latest lens has "PZD" or Piezo Drive AF. Those lens have several switches on the side of the lens which allows you to use it with Auto or Manual Focus as well as stabilization or not. Have you not used the correct switch positions? Please clarify as this could cause a lack of sharpness. For what it's worth, back in the day I could handhold this type of long zoom at 1/30 or 1/60 second. Now I find I have no sharpness problems at 1/125 sec, even if I have to use a higher ISO setting.

I have two 28-300MM Nikkors that I use with my D800s and D3S and get great results for my portrait and model photography. I do have Nikon's range of DX long zoom lenses as well including the 5.6 version of the 18-300MM and I have no complaints with any of them! I've also bought and researched using new and past versions of Tamron, Sigma and Tokina long zooms for both my FX and DX cameras and on the whole are pretty good in terms of quality when using its "sweet spot" and a decent shutter speed. I even purchased via eBay a 28-300MM Vivitar F4 lens from the 70s (?) made by Cosina which is not so bad considering its age and lack of stabilization.

Cheers! Be well. Ed