Just got the Tamron 35mm f/2.8 Di OSD M 1:2, as part of a sale (lots of camera stores having virus-related sales at the moment - some people binge eat when they can't do anything, but I seem to binge buy lenses...).
Now, it's not the fastest prime in its focal length. The optics are great. AF is slow-ish, isn't silent, but is accurate. Construction is adequate - better than a kit lens, not as good as a Canon L or Sony GM (or high-end G) lens, but is weather-sealed. It weighs very little in an absolute sense, but isn't a lightweight considering its focal length and aperture - the Sony 35/1.8 is the same weight but is over a stop faster, better-built and with faster AF, although not better optics. It has some focus-shift and significant focus-breathing - at close focus distances, its magnification is significantly greater than at infinity.
So, why did I get it? It has a maximum magnification of 0.5x. Normally, you'd rarely use a 35mm for macro, especially for wildlife. But the purpose of this lens isn't to shoot bugs from 5cm. Rather, it's for shooting frogs, small lizards, larger flowers and the like from 20-25cm - subjects calling for a magnification of 0.25-0.5, where a more typical lens wouldn't provide sufficient magnification, but a typical 90-105mm macro would require far too great a working distance to illuminate with off-camera flash that's still attached to your macro rig (requiring a separate light stand or assistant to hold it).
And, in this role, it seems to do a fantastic job. AF is slow, but this is almost universal with macros. It may be noisy and have focus breathing, but I'm not shooting video. AF accuracy is good. It takes up little weight and space in the pack, as a companion to the 90/2.8 for macro-shooting night hikes. I can shoot a semi-macro subject at 20-25cm while illuminating it with flash units attached to my macro rig, whereas, with the 90mm, I'd have to stand further back and set up a light stand - not always convenient in the field. And it's sharp. (It also works as a sharper alternative to the 24-70/2.8 for stitching panoramas, but that's besides the point)