Question about Ubiquiti UniFi AP-AC-HD

I also use several "UniFi AP-AC-HD" distributed over several floors in the house, as well as another one that covers the surrounding area from a conservatory.
At least the "AP-AC-HD" product from Unifi supports both technologies "Zero Handoff" and "Fast Roaming", which can be set via the software.
However, since I have a relatively large number of WLAN clients with the Smart Home Automation, I decided to use "Fast Roaming", which allows me to switch between the APs almost seamlessly.
In reality, I don't notice very much of the change when there is movement during normal WLAN use, e.g. via a smartphone/tablet, but if I observe closely, I can already see that a micro-interruption is taking place. However, depending on the end application, this is hardly noticeable.
However, if I use end applications such as VoIP, the situation is somewhat different, and the change is noticeable with a clear short interruption or noise, despite optimised WLAN settings.
This is where Ubiquiti differs from more expensive enterprise products, such as those from Cisco.
In terms of the price/performance ratio and from the perspective of a "home" or "SME" environment, the use of Unifi APs (at least with the Pro or HD products) is now a viable and scalable alternative.

I have several Unifi APs in the house distributed over floors. The handover from one to the other works perfectly.