I also use voice to start timers, probably more than once a day on average.
Which is why, by now, the idiotic and unfunny jokes Siri makes almost every time I do that are really fucking annoying (even though it doesn't say them out loud, and I just have to see them printed on the screen).
You can tell their engineers never continuously tested Siri's responses for multiple weeks. I'd rather have the "Ok" than Siri's 5 other longer responses, and the one sassy response.
'Set a timer for 20 minutes' is faster for me than using the clock app.
'Navigate to the nearest gas station' is faster.
Setting reminders is usually faster with Siri. Especially geofences ones.
Finding pictures in a location is much easier with Siri.. "Find pictures at Lake Tahoe"
The main problem is that you have to remember what you can do.