The first Tamron lens to feature ring-type, ultrasonic focus, the Tamron SP 70-300mm f/4-5.6 Di VC USD is a major step up from the company's older, non-stabilised 70-300mm Macro lens. Build quality is vastly superior, and Vibration Correction works extremely well. Sure, you lose the 0.5x macro facility offered by the older lens, but in every other respect, the VC USD is a much better choice.
Ring-type ultrasonic autofocus and Vibration Correction are well implemented and work very well.
The lack of sharpness when shooting at 300mm with an aperture of f/5.6 is disappointing.
The only disappointment with the Tamron SP 70-300mm f/4-5.6 Di VC USD is a lack of sharpness at the longest telephoto zoom setting, at anything outside an aperture range of f/8-16.