a7sii and metabones ... af performance?

i have bought myself an A7SII ,, Video from this camera is Awesome .. the ISO i can get away with compared to cameras i have is unbelievable..

i understand that stills arent its strongest area .. i can tell the difference right away from my 5d3 and even my panasonic gx8 ? ..
but i think the pictures are acceptable as of now ..
i wanted this camera because of its low light ability and video capabilities and i understood that its pictures wouldnt be the best sony has to offer so i'm ok with what it is
to be fair i've been manual focusing , so it probably is a little better than i'm getting due to my lack of experience manual focusing ..

i have a sony 16-35 f4 on its way..

i still have my 5d3 and canon glass .. and for right now i dont intend to get rid of it ,, there is plenty of info out there as to how the sony a7rii and a6300 does with metabones .. but not much for the a7sii , well atleast not for stills ..understandably this camera is more popular with videographers

but ,,i wanted the 16-35 to be native since thats the lens that i'd use most for pics and video,,but aside from this sony 16-35 since, i'm keeping the canon , it would make sense to buy other lenses that i would want in Canon mount ..

I currently have a Fotodiox Adapter , which has AF .. but its so poor that you might as well MF..
so , the question is , is it worth buying a metabones for A7Sii ? Does the AF work well ?
anyone have any experience with this combo ?
this is for still pictures of course

You'll likely have much better results from the native lens that is on it's way. The A7Sii is CDAF only (contrast detect). It will be very accurate when it does lock focus, but performance will be pretty poor compared to what people can get on bodies with PDAF (phase detect) like the A7Rii. Performance with CDAF will be much more like when you're AF'ing on your 5D3 in live-view, which also uses CDAF. As far as I know, most third party adapters rely on PDAF to make the magic happen, where you hear about people getting AF performance on their Sony that's as good as on their Canon etc... Since the Sii doesn't have PDAF, I don't think you'd experience much of a boost to performance by upgrading to the premium Metabones.

But I could be wrong. Someone, please speak up if I'm outdated in my info

Thanks
i found this https://www.youtube.co​m/watch?v=OzK5ARJqoEs

and yeah doesnt do well at all.. for the reasons you mentioned , as i did some res

thats more or less how my fotodiox does .. and sometimes i get the confirmation green light and beep and its not in focus ..

what i actually found that works quicker and more accuratly is to do a quick manual focus then hit button to look for fucos it which point it does ... or atleast more often..

ok so anyway yeah i guesss for now No metabones for me.. i'll just continue with the Fotodiox and manual focus when i want to use my canon lenses