That way the intent is obvious even when the introductory if() clause is scrolled off of the top of the editor window

For a counterpoint, from the same line of reasoning, I drew the opposite conclusion.

I put the shortest block in the if part, and the longer block in the else part, so the introductory clause is still visible in the editor window when you're reviewing the second part of the conditional. It becomes easy to say "yes, I'm here because that conditional just up there evaluated to false", because you can see it.

If both sections are so long as to not fit in the window, I'll probably wind up breaking them both out into separate subroutines, because, by definition, they're doing an awful lot of stuff.

Getting back to the OP, I'm a big fan of early returns, as it keeps the code closer to the left hand side of the screen. I'm a bit more leery of early exits. I dislike when some deeply buried routine decides it's time to stop the show (although END blocks can alleviate the problem of tidying up database connections and so on).