I had a 24mm Sigma about 25 years ago, it was a dog of a lens, flare was bad, pin-cushion distortion, so I got rid of it.

I hadn't learnt my lesson when a few years before I bought a Sigma 80-200 zoom, after two weeks it kept zooming and came apart, the replacement had a faulty aperture mechanism, and the third didn't focus at infinity. I refused the fourth and bought a Mamiya C33 instead.

The build quality was awful, never had a problem with Vivitar or Tamron, but always bought the S1 or SP lenses.