NorBro
Major Contributor
I dont have experience with those specific lenses but in general, you're going to want Sigma over Tamron. Tamron used to be considered a "mud" brand. While they have
imnproved a bit, Sigma has shot to the top, often more desirable than OEM brand lenses with their ART lineup. That feat is kind of incredible for a third party lens brand.
Sigma's ARTs were hot 2014-2017...it's been a while now and others make a lot of great glass.
Mentioned this the other month, but Roger from LensRentals who's highly respected for his glass knowledge thinks the Tamron 35mm 1.4 is currently the best 35mm lens in the world. That includes being put up against Canon's 35mm II!!
Sharpness, quality, bokeh, colors, contrast, coatings...these are all things you don't have to be concerned with as much with a lot of the more expensive options from everyone these days.
It's only pristine AF support that's a thought.