I wanted to get a lens exclusively for shooting portraits - have the Nikon D500.
Compared a ton of lenses in the 50-85mm range, wanted a shallow depth of field/wide aperture/nice bokeh.
Narrowed it down to the following best options based on the pictures I saw taken by people who own these lenses:

- Voightlander 58mm f1.4 - very nice lense for the money: but not auto-focus.

- Zeiss Otus 55mm f1.4 - super nice pictures, but at $3,990 new, it's waaay out of my price range (and no AF)

- Sigma 50mm f1.4 Art Lens - very sharp lens, but really big and heavy, and so many of the images I saw just lacked character (a bit 'sterile'). Found many used copies selling for $500 or less, which tells me that people who bought the lens weren't particularly happy with it in the long run.

- Nikon 58mm f1.4G - this lens has a really wide range of reviews: from people complaining about Chromatic Aberration and 'over-priced' to others gushing over it's 'smooth bokeh' and 'unique character'.

+++

So I kind of narrowed it down to the Sigma 50mm and the Nikon 58mm. Read just about every review and watched every video I could find. I noticed that over time, even the critics who hated on the Nikon 58mm at the beginning warmed up to it over time, with many ultimately falling in love with the lens. Many of the reviewers called it 'special' and that it had an indefinable 'character'... and many of the pictures I saw taken with this lens took my breath away.
The Sigma just didn't instill that kind of bond in any of the reviews I read.

I went ahead and found a great deal on a used version of the Nikon 58mm at KEH for only slightly more than the Sigma 50mm costs new - it came with a 6 month warranty, and was pretty much like-new when I opened the box.

Suffice to say, I'm very happy with the results - took this shot of my buddy the night I picked it up (low light, in the streets of Hong Kong).