It really depends if people are talking at the same time or not. If in a close group (space matters, the mic only goes ~2-3m), one person talking at a time, then they're great. That's the setup I most often have at conferences, so it's been great there.
In evenings/parties, it's a bit more chaotic, and the glasses tend to fall off for sure.
Regarding distinguishing different speakers etc I haven't needed that, I use the glasses as a helper, they fill in the gaps. So it's "just a stream of words", but it has been enough to already help a ton.
The directional mic does work quite well, but sometimes you have just 2 conversations happening in front of you and it's not working at all. In other setups (especially professional ones), people usually speak one at a time and it works great.