[Klaus]

https://opticallimits.com/sony/sigma-16-28mm-f-2-8-dg-dn-contemporary-review/

Quite nice actually

[borisbg]

Good alternative to Tamron 17-28.
Thanks for your review!

[thxbb12]

Thanks for the review, Klaus.
Better IQ than expected.
That makes for a very nice UWA zoom at a reasonable cost.

[Rover]

Thank you for the review, Klaus. Looks like a nice lens, quite a bit better than the Tamron 17-28. They should have added the "26" mark on the zoom ring, though - just for consistency.

I also happen to love the way the lens looks, I think it's similar to the Sigma 24-35/2 which I thought was (almost) the most beautiful lens ever.

[toni-a]

Size and weight of this lens compared to competitors in the pre digital correction era, show how much relying on digital correction can help reducing complexity of design and size of weight of lenses.
Would you get this one or a lens twice its weight with far less vignetting and distortions ?

[Rover]

I would say the native aberrations aren't extreme, certainly not to the level of some other lenses tested in this space recently. Which translates to good output performance.

[toni-a]

Well 3EV vignetting isn't extreme by today's standards, in the past it was a different story, also distortions aren't extreme, Sigma engineers doing very good jobs

[Rover]

3 stops of vignetting were always par for the course for full frame wide angle lenses or fast lenses in general. 4.5% of distortion weren't, but 3.5% were also "normal". Just saying... :-)

[toni-a]

3 stops of vignetting were always par for the course for full frame wide angle lenses or fast lenses in general. 4.5% of distortion weren't, but 3.5% were also "normal". Just saying... :-)

Here's a review from 2014 , Klaus considered 2 EV to be excessive 
Canon EF-S 24mm f/2.8 STM - Review / Test Report - Analysis (photozone.de)

of course it's a relative thing and how important it  is for you.
Personally it's not a serious issue, I call vignetting extreme when corners are black, like on Sony 16-50, it's actually distortions correction that crops away black corners that removes vignetting and not vignetting correction itself !!!, the lens isn't usable at 16mm without digital correction

[Rover]

24/2.8 STM is an APS-C lens, the measuring stick is / was different for those (remember how the vignetting scale for FF is marked for 3EV, but only for 1.5EV I'm the case of APS-C lenses?)