Brian Smith published two eagerly awaited columns in the past few days covering Canon adapted lenses and our options for a Superzoom. http://briansmith.com/best-150-600mm-superzoom-for-sony-a7rii/
There was good news and bad - mostly bad for those of us expecting to use our a7R2 for bird photography where good autofocus and long focal length are essential. But, the one bright spot for me was Brian's comments about the Tamron SP 150-600mm F5.0-6.3 Di for Sony A-mount. To quote Brian, "Tamron’s Sony A-mount 150-600mm ROCKS the AF!" Pretty high praise and pretty exciting stuff for this birder!
But, with all due respect for Brian's many skills, I don't associate him with serious birding.
Is anyone yet using this combination for wildlife/bird photography?