There are many areas where Google gives a lot more detailed answers too, like film casts, biographical information, discographies etc. so you're being quite selective.
LOL, I figured somebody would challenge me.
OK, here we go:
For the rest of this, GS = Google Voice Search, SR = Siri
"Show me the cast of the original star wars movie"
GS = just did a web search
SR = showed me all of the star wars movies in a cute movie themed list and you could touch each one to get the cast and info
"Show me the cast of saving private ryan"
GS = just did a web search
SR = showed me a movie posterish looking card with all of the movie info
"Who was John F. Kennedy"
GS = Showed me a nice info card about him and said a few facts
SR = Showed me an info card from WolframAlpha
"show me the Beatles discography"
Neither one of them understood what I wanted and just did web searches, I finally just said "Beatles discography"
GS = Showed me a cool scrolling horizontal list of the Beatles albums.
SR = brought up a WolframAlpha card with the info
"who won the lakers game last night?"
GS = told me who won (The Mavs dangit!) and showed web results
SR = told me who won and the final score including a cool looking scoreboard card with the score by quarter
"when do the Lakers play their next game?"
GS = told me the answer and showed web results
SR = told me and showed a nice card that showed the teams records and what channels were showing the game
"Show me the Lakers roster"
GS = did a web search that showed an ESPN short list of players that was mostly inaccurate
SR = showed me a card with all of the players and their picture, number, height, weight etc...
"what is Kobe Bryant's scoring average?
GS = Just did a web search
SR = told me his average and showed me a card with all of his stats on it
"How many calories are in a Big Mac?"
GS = did a web search (the first listing did show the calorie count below it)
SR = showed me a WolframAlpha card with the details
Shall I go on?
😀
Don't get me wrong, I think Google's voice search is really impressive. Much better than Siri at Google searching, but I feel so far like Siri is still better at answering many info requests that don't involve OS integration.