With the new home button? I find myself having trouble using it - specifically getting the timing right. More often than not I activate Siri and while speaking I get, "sorry, I didn't get that," or some other garbage. It even happens when I say a really short command, like "open Yelp," or something similar. It's pretty frustrating. Out of frustration I just enabled hey siri lol. It's just a little annoying. I don't use it all that much anyway since Siri is pretty useless and not very smart (opinion), and only use it to open apps one-handedly while driving or something.