With zoom lenses, you usually have to pick fast and expensive, or slow and cheap. But with modern IBIS and lens stabilization, could slow and cheap by more viable?
My first experience of a 70-300mm with a variable aperture was just about as bad as you can get. I bought an outdated, second-hand, 70-300mm with a similar aperture range to this Tamron, though what I bought was not Tamron. It was built like I'd just won it from an arcade, its autofocus was slow and lazy, and its images were softer than a freshly shampooed sheep. I quickly sold it and developed an unreasonable hatred for both 70-300mm lenses and variable apertures.
But that was over a decade ago and we've come a long way. The new Tamron 70-300mm f/4.5-6.3 Di III RXD for Sony E mount does appear to be good. Its autofocus seems responsive, its build quality seems adequate, but its real perks are elsewhere. Firstly, it weighs very little indeed, at just 545g. Furthermore, it's $549 brand new, which is probably its most appealing factor.
For those worried about bokeh and subject separation from the background, at 300mm, f/6.3 will blur your background just fine for portraiture. 70mm at the other end would be fine too in most cases, though you may need to get reasonably close to your subject.
Will you be buying this affordable zoom?