So, slipstream is fiction that appears to follow the conventions of mainstream fiction but it has strangeness in it (and this is different from magical realism in some way I can probably see but can't articulate) -- correct?
Speculative fiction is when you want to belong to the genre but not too fiercely, and you want to distance yourself from conventions of fantasy or science fiction that you don't want to invoke in your writing, right?
Now, when you have a matrix of either sceince fiction or fantasy in a story but there are elements of the other, and it's not sloppiness but what you intended, what do you call it?