Latest on twitter:

"For example, when I tap on something, I don’t have to hover for five seconds wondering “now did it get that tap, or do I have to do it again?” This is something other platforms are still struggling with."

stevenf.com - A couple people have asked me to post an update… Oh come now, sure you do. The iPhone UI may be more responsive than the competition, but there are plenty of times it lags for me, even on a new 3GS, even using the built-in apps.