Always the danger of using 3rd party services -- their downtime is your downtime. I try to use few of them.
I always thought their posts were kinda neat about racking odd shaped Apple hardware in the datacenter. But it very much seemed to me like a software problem -- I would think it's much easier to build competing image scaling libraries that do not require Mac hardware and software.
And it made me think that they had just hired like datacenter guys with a passion for Apple kit -- a supreme case of where if you have a hammer, everything looks like a nail.