I like each of the Big 3 Generators for different reasons.
Dalle2 - best for 'digital art' that is like a painting. The right mix of quality and simplicity. The inpainting and outpainting works really well.
Midjourney - best for magical, mythical or wild images. Can't really do 'normal' stuff as well and no inpainting outpaint or API makes it harder to use.
Stable Diffusion - Use for everything else. I use for experiments. Since I can run it on my own equipment and it is 'free' I try tons of prompts. Different models and open source means you can really customize it.
Summer Bod 2020