Depends on what you want to do. Bing (or rather DALL-E) is pretty unique in its approach to produce great results with simple prompts. And also it has by far the best understanding of scene descriptions I've seen so far.
Midjourney is superior in producing life-like results and far superior with doing close-ups and detailed faces and so on, but its filters are even stricter than Bing's and it's not easy to especially make wet content.
With Stable Diffusion you can do pretty much anything you like, either using it locally or hosted online with services like graydient.ai which do not filters or censor anything and let's you do adult content aswell. On the downside there are a zillion of Base Models and LoRas around which you'll need to play around with and you have to be very descriptive, both of which is very time consuming compared to simple all in one solutions like Bing.
Well that's really interesting as they both should be exactly the same. Or maybe a country thing? Since a couple of weeks Bing is labelled as "Bing Image Creator by Designer" and when I'm logging into "Designer" with my MS Account it also shows my latest Bing creations.
Edit: funny, there seem to be different incarnations around. With the one from your link I don't see any of my old generations, however at least for my prompts it is way more restrictive than Bing and blocks almost everything I'm trying to do.
Love you, too
