I still maintain that it's a spectrum, with some things certainly belonging at one end or the other, but with many things in between.
I will say, though, when I'm reading something categorized as SF, but I find some element of outright magic, it bugs me. As soon as there's magic, or an element that doesn't seem to have any sort of scientific basis at all, it moves out of SF into that middle ground for me. And it might be just personal preference, but the reverse isn't the same for me. I feel like a story can be fantasy and still have elements with a scientific basis. Again, I'm very willing to admit that that's a personal bias.