I think this confuses the reading of block levels. I think there should be a blank line above every selecter, regardless of position. It's more consistent with the reading of rules, whether they're there or not.

```sass
.class
    margin: 0

    .child
        margin: 0

    .other-child-without-rules

        .next-level
            margin: 0

    .class-with-toggle
        margin: 0

        &.toggled
            padding: 0
```