I found this mic by pure chance, while I'd known the CX-516 and 508 for long. I now own four pairs of it.
I use it live, for overheads or to mike instruments up.
Very sensitive -like all condenser microphones-, it allows to mike instruments not equipped with a pickup (such as mandolins, ukuleles, banjos...) whithout requiring the musician to stick to the microphone. I also use it to mike several instruments at once, in "classic" overhead way or for moving sources like accordion bass sounds or bagpipe drones.
Even positioned far from the source, it renders good dounds that are totally usable in live situations.
It's not much feedback-prone, but it doesn't mean it can be used as a dynamic mic
Its very short body allows to place it in hardly accessible places. Up to two can be put in the included pouch, as they're often used by pairs...
In a nutshell:
+ Reasonable price
+ Flat bandwith, making it very little prone to feedback
+ Good sound, even far from the source
+ Small size
- Very short body, which is not always practical in some circumstances