There are a few interesting differences between the 12" and the 7" release. Although they both feature the same artwork on the front and back, the back of the 12" has an additonal still photo of Kate from the video. Like the 12" for Running Up That Hill, Cloudbusting also has an extremely flimsy picture sleeve, which is evident on mine as it's sustained a bit of edge and corner wear.
The next interesting thing about the 12" is that, instead of the album version of Cloudbusting (or even the video mix), we get the Organon Remix. I'm sure this was a marketing strategy to get people to buy the 12". Lots of singers and groups did things like this back in the day because it was something "new", and back then, it was basically the only way you were going to hear it or get it.
I also find it interesting how the labels for the 7" and 12" are the only ones that differ from the rest of the Hounds of Love singles. And, unlike the 7" single, which has an inscription in the run off vinyl, it's not to be found on the 12" version. I find that odd because usually if a 7" had an inscription on it, you usually found it on the 12" as well. Not always, but usually.