sanj
A very good review, unlike the eulogies from those who want you to click and buy from Adorama etc. The lenstip review looked good, and they are usually fair. ePhotozine didn't give it 5 stars. A pity you sold the 200-400. If it improves with more AFMA etc, let us know.
Thanks.
Edit: this lens doesn't appear to have captured the imagination like the Tamron 150-600 did, and there is not much interest in replying on CR.