Meh. Besides the search for dog pictures the speed differences between the phones wasn't significant, IMO.
The biggest differences I noticed was that although Siri has a less human sounding voice she is programed to responded in a more human, conversational tone where as the Google phone has a more human voice but responds more like a robot. I also like how Siri repeats the reminder back to me (so I know it's right) as well allows me to do the whole process via voice. I set myself reminders all the time in the car or walking around and having to finish a voice-initiated task like that by looking down at the screen is much less convenient.
Lethal