Realistic is the wrong search term

Almost every product in this category produces realistic output now. Searching for realism sorts on a dimension where nothing differs.

What you are actually looking for

A portrait that still looks like you. The failure people hit is not implausibility — it is that the headshot resembles a professionally photographed person who is almost them.

A jaw slightly narrower. Eyes sitting slightly differently. Nothing you can point at, and yet people who know you notice something.

How to test for it

Generate twenty images. Mix ten with ten real photographs of yourself and ask someone who knows your face to sort the pile. If they can sort reliably, the likeness is not there — and no amount of realism compensates.

Where the gap is widest

Faces further from the average: strong prescription glasses, tightly curled hair, darker skin tones, pronounced asymmetry.

The ten-minute version

Run your own face through a free tier before paying anything. It answers the question that no comparison article can answer on your behalf.