[Klaus]

The FE 200-600mm is substantially shorter than the Tamron 150-600mm at 600mm actually - it doesn't extend ... and when counting in the adapter it is as heavy. Tamrons are also generally lighter due to different materials so the comparison isn't totally valid. ;-)

However, I don't think that - on equal grounds - there's more than 10-20% in it. There'll be no equal grounds anymore though. It is becoming increasingly unlikely that CaNikon will ever release new DSLR lenses.

And all that is the point - you'd always prefer new, dedicated mirrorless lenses over adapted legacy lenses - because they are better or smaller or both.