Tracking: Good performance for tracking subjects, including birds in flight.
Video Performance: Excellent autofocus for video, minimal focus breathing.
Image Quality
Optical Design: 15 elements in 12 groups, including low dispersion elements.
Center Performance: Very good; better than competitors (Sony and Sigma).
Vignette & Distortion: Mild barrel distortion; vignette is a non-issue.
Chromatic Aberration: Excellent control over longitudinal and lateral chromatic aberration.
Bokeh & Color
Bokeh Quality: Nice circular highlights from 12 rounded aperture blades.
Color Rendition: Good color performance; suitable for landscapes and night photography.
Additional Information
Flare Resistance: Decent; minor loss of contrast, improved at smaller apertures.
Minimum Focus Distance: 23 cm, allowing for close-up shots.
No dedicated AF-MF switch: Function button can be programmed for this.
Conclusion
Overall, the Tamron 90mm f2.8 Di3 Macro VXD lens is a fantastic total package, providing great value for its price, along with impressive autofocus and optical performance.
Recommended for both macro photography and general use.