Awagi TouchMarks has claimed that Android phone are twice as slower as iPhones. Even the latest and greatest S4 still has a slower minimum app response time as the iPhone 4S, which came out almost 3 years ago.
Some might argue that this test is irrelevant but I dissagree. Having used an iPad for a year and going to the Nexus 7 tablet, the difference is night and day. This could be why users coming from iOS devices claim the typing on iOS is Much more snappier than Android.
This is a big deal for musicians who plan on making musical on tablets or even small projects on phones. Or artist who like to make a quick sketch on a tablet. Even those who do a lot of typing on their devices, you might want to consider an iOS device if you need something more responsive.