Photography Blog has completed their review of the recently announced and available Tamron SP 150-600mm f/5-6.3 VC G2. It appears the new Tamron is an improvement over its predecessor.
The second-generation Tamron SP 150-600mm F/5-6.3 Di VC USD G2 offers better image quality, more features, faster auto-focus and more effective image stabilisation than the 2013 version, but the price has increased significantly, so it's not quite the out-and-out bargain that it once was.
The Tamron SP 150-600mm F/5-6.3 Di VC USD G2 offers improved image quality with smooth bokeh and excellent sharpness, a very effective and versatile image stabilisation system, and a fast, quiet and reliable auto-focus system. Despite a modest increase in size and weight, Tamron's optic is still smaller and lighter than the Canon and Nikon equivalents, despite offering a bigger, more versatile focal range. Read the full review
Tamron SP 150-600mm f/5-6.3 Di VC USD G2 $1399 at B&H Photo