This code is worse in every way than a simple if/elsif/else block. But far easier to understand than a series of nested ternary operators (?:), which is about what I'd expect to encounter.
Given the typical expertise level of PHP hackers, and the inability of even experienced coders in other languages to use it correctly, I'm glad there's no support for threading in PHP. I'm sure they're planning to tack it on in the next version, though.