Just installed the (older) ZBmini-l, not the 2, but it’s indeed a noticeable delay.
It’s not terrible, but the regular ZBmini reacts much faster.
The benefit for me is mostly the ability to hook up multiple switches with just the end wire. I have some AliExpres switches on the way that have neutral and also support this. The ZBmini only supports switching from a loop.
Edit:
Looking at this post, 8 hours in and it’s not responding anymore 