So cheap and handy that it makes sense to fit one on every stand in your kit : it's sturdy enough for heavy condensers with suspension, and that's where this coupler is most useful.
Not only is it a time saver, but it encourages experimentation with mic changes and placement.
The only downside is there's a bit of rotational play, due to the design and mechanical tolerances, which means it's not 100% reliable for applications where consistent alignment matters — stereo pairs and shotguns mics, mainly.