i have 1.7 teleconverter and still own 70-200mm F/2.8. was thinking to hold on to my 150-600mm gen 1 tamron which is Full manaul on Z6. instead of replacing it. thought about getting new nikon 120-300mm with my 1.7 teleconverter to make it 205 to 510mm with F/4.6 stop compared if replaced my 150-600mm for 200-500mm F/5.6 or 5.6-6.3 with third party's 150-600mm F/5.6-6.3 so what would you do. if in my shoe