Questions on the Sigma 100-400mm vs Tamron 100-400mm?

[snerkler]

Has anyone used these (preferably both) and can say how good they are and how they compare? I'm contemplating getting one of these as a lighter alternative to my Tamron 150-600mm G1, and also as a motorsport lens. I rented the Sigma last year and was impressed with IQ but OS (VR/IS) wasn't great, and AF was 'reasonable'. Apparently the Tamron has better AF and VC (VR/IS) and IQ is also very good, but I'd like to know how it compares to the Sigma.

Also, the Nikon 153 point AF system (at least on the D850 and D500) has a slight issue with the Tamron and Sigma 150-600mm's in that past 520mm only the few f8 sensitive AF points work, therefore you can't use extreme corner AF points etc. and I wonder if the 100-400mm's are the same as they're also f6.3 (I had the D750 when I tried the Sigma last year). If anyone's used either of these lenses on the D850 or D500 do all AF points (including outer corners) work all the time?

Any help would be appreciated.

 

[mikew]

As you know i had the Sigma and liked it, cant remember how well the outer points worked on the D500 though, my main dislike was no facility for a tripod foot to fix my black rapid strap to, good point for me it played well with their 1.4 converter on the D500.

 

[JJ!]

You don’t need one. Just walk closer