All the things that made the Pentax version of this design an Editor's Choice apply just as well to the Tokina Opera version, bringing some fine qualities into the domain of Canon and Nikon users.
Excellent sharpness, Very even performance, Well controlled CA, Zero distortion, Lovely smooth bokeh, Fast, silent and accurate AF, Weather and dust resistance, Quality manufacture, Full-time manual focus, No flare
Price tag, Heavy, No inbuilt shake reduction