Tamron AF 18-270mm F3, 5-6, 3 DI II VC PZD?

What do you think of these lens and this brand? Any advice appreciated.
Tamron AF 18-270mm F3, 5-6, 3 DI II VC PZD (for Nikon)
Planning to buy this and Nikon D3100 with 18-55mm VR kit

Super zoom lenses tend to have optical issues, and this lens is no exception. If you need a super zoom, go with the Nikon 18-200mm which is not quite as extreme.

Even the Nikon 18-200mm is marginal at apertures wider than f/8. I have that lens, and if I shoot f/8, it provides acceptable quality.

Superzooms are essentially daylight lenses.

http://www.althephoto.com/lenses/super-zooms.php

It's very convenient but offers rather mediocre image quality.

There would be no point whatsoever in buying this in combination with the 18-55mm kit lens, as the kit lens doesn't do anything that this lens can't do.

I bought this lens for my Sony SLT-A77 as I felt I needed a "quiet" lens for everyday and video use. I have to admit though having read the reviews first it was a tough call. On the SLT-A77 it certainly seems to out perform the reviews, but that may in part be down to some craft tricks the Sony image processor get up to.

From my experience it's an okay lens for what it does, but it's not my favorite. However if you are planning on this lens I'd wonder why you are going for the D3100 with a kit lens that cover just a subset. I'd just get the 18-270mm lens and the body, and put the money you save by not having the kit lens towards your first "specialist" lens.