There is a significant audio delay in both directions (Cam to Phone App and Phone App to Cam), about 5 to 10 seconds, while monitoring video, while using "Talk" button and while using "Voice Call".  The video does not have this delay in monitor mode(other than at Mobile App startup, where it takes about a few seconds).

Note that WiFi signal is excellent, Mobile is connected on the local WiFi (both Cam and Phone on same WiFi) and video is also excellent.  No Video/Audio recording taking place, although an SD card is inside.