If you're on wired internet, if you aren't saturating your local network, if your provider isn't having any issues, if their servers are up, if there is no DNS delay or caching issues, if...
Relying on the internet for "real time" computation is a recipe for inconsistent behavior.
The fact that people are using these features of android and apple phones shows that it's 'good enough'. I frequently use it to issue navigation commands on my phone and it fails maybe 1 in 25 times. Well worth not typing in destinations when I want to go somewhere quickly.
