Actually I disagree. Well, if you mean "smoother" by interface then maybe. But I actually compared the new Google Maps on iPhone 5 with Google Maps on the Note 2 and the swiping/scrolling lagged a little on iOS whereas it was totally smooth on the Note 2. Same went for zooming in or out with double tap/two finger tap and pressing the locate me button. Also, "Maps" for iOS 5 and prior did NOT lag whereas the new app from Google does a little even on the iPhone 5.
No lag on my iPhone 5!