Another comparison: Adafactor vs Prodigy.
The Adafactor is slower to train and holds the prompt better on these lora. The lora trained with Prodigy is strong and the training is fast, (4th epoch seems to be good if it's just a face). After that it picks up other features (hair, body shape, tattoos, etc.)
So for a person I prefer Adafactor, for a style or concept I prefer Prodigy, but if you need a realistic person you can use Prodigy for that too, but you may need Clip Skip 2 or 3 for flexibility when generating person images, because Clip Skip 1 is just an image generator, nothing more.