No experience with the lens, but some good reviews. I'm looking at this lens also.
DMF wrote:
I currently use a Nikon 80 - 400 4.5-5.6 lens, it is very heavy difficult for me to use without tripod, considering buying the much lighter Tamron 18-400. While I will use a tripod when I can, the weight of the lens would allow me to hand hold. Does anyone have experience with this Tamron lens? Doug