They are run by what is arguably the largest hosting provider[1]. It's definitely going to "work" mind you, but outside of EU the speeds may be a tad abysmal.
It's standard OpenStack storage and it's possible to mount FUSE drive, so no terrible client. I use it and have no complaints, just don't expect 1 ms read times as a mounted drive, etc.
https://hubic.com/
Maybe someone can comment if they've used them in anger.