Sigma vs Tamron 150-600mm on A7s?

[Athiril]

Picked up A7s recently, love it so much, and want to get one of the 150-600mm's seeing as how well they perform optically at the long end, I don't mind the slow aperture given the ISO performance on this camera.

 

That leaves me with essentially two options.

 

The Tamron 150-600mm + LA-EA4 adapter, which leaves me with no stabilisation (since Tamron did not put VC in the lens on the Alpha version?) if I understand, but fast AF right?

 

And the Sigma 150-600mm + Fotodiox/Metabones, which gives slow (next to useless as I understand it) AF, but gives lens based image stabilisation?

[mtman]

I tried the Sigma with Fotodiox on my NEX-7 before I got my A7RII, there was no communication between lens & body so no focus or F stop control. I tried another adapter with slightly better results (intermittent F-stop). I returned both for refund. Someday I'll try the Tamron with a Sony adapter.