If I had Siri plugged into a dock...that takes care of the sound part. What else does it do that Siri can't?
Just a few things off the top of my head. I know that with Ios8, Siri can do more things but not sure since I never use it on my Ipad.
The average person would need to buy a dock.
What happens when you ask Siri to give you the news?
What happens when someone else in the family wants to use Siri but you're gone?
Does the Iphone wake up for voice commands?
To be honest, if you already have a docking station and an Iphone then you probably don't need it. I look at it as a cheap ($100) bluetooth speaker that can also do other things. I have a bunch of friends who have paid $200+ for bluetooth speakers that are just bluetooth speakers. The one big downside I see for some people is no battery.