The Tamron 70-210mm F/4 Di VC USD (Model A034) provides good value for the price, especially if you want to add this popular focal range to your lens collection. The f/4 minimum aperture shouldn't be an issue unless you want (or need) an f/2.8 for low light shots or extremely shallow depth of field.
The Tamron 70-210mm F/4 Di VC USD (Model A034) is relatively compact and lightweight so it won't weigh you down; Thanks to its internal zoom, the physical length of the lens remains constant throughout the focal range, as does its f/4 aperture.
A tripod collar will cost you extra and autofocus may search in low contrast conditions; There's minor vignetting and the lens is available only for Canon and Nikon (no Sony option), Minor vignetting, Occasional focus hunting, Tripod collar extra, Available for Nikon and Canon only