Have you used and compared the FE 300mm F2.8 GM OSS with the 2X teleconverter to the FE 200–600 mm F5.6–6.3 G OSS for birds and other wildlife?
I'm considering the FE 300mm F2.8 GM OSS (I already have the 2x teleconverter) to replace the FE 200–600 mm F5.6–6.3 G OSS.
I've scoured the web but...