I have to strongly disagree here. I'm a mobile dev, I work on Android and iOS. My main phone is an iPhone 5s, recently I tried switching OS just so that I would be more comfortable with the different OS's day to day idioms. I couldn't stand Android, it was sooo laggy feeling compared to a iPhone or even a windows 8 phone. Both Apple and Microsoft have large leads in user experience and speed. Don't get me wrong Android is certainly better than either in it's own way but performance and responsiveness are not it's strong suite. 3 apps that the difference was obvious to me are: Google Maps (the ios version feels way smoother), Evernote, and the facebook app. Also see the yahoo weather app the difference was incredible. Phones I used in testing: HTC One, Samsung S4, Nokia Lumia 1520, and iPhone 5S
Granted all of this was based upon personal experience and isn't a scientific study but to me the difference was absolutely clear. Perhaps if I had only used an Android device I wouldn't have noticed the difference as much but having been a long term iOS user I could not stand it.
Thanks for including that line, because my personal experience is the exact opposite. I have a four year old android phone and I dread any time I need to use my wife's one year old ipod. I find the lag on the ipod slow to the point of almost being unusable. Every time I use it, there's at least one point where I'll put down the iPod to go do something else while I wait for it to catch up with me.
It's amazing how much personal experiences can differ.
Edit: updated possibly relevant details
Honestly, try a Nexus 5 if you get the chance. The hardware in the phone makes a huge difference (and it's often in places that aren't benchmarked, like the touch controller).
[1] we have three iOS devices and I'm the loveless tech support for them.
The biggest tragedy is that Google had a chance to make a better NDK experience with Android Studio, but instead they chose to ignore it completely. With Eclipse you at least had an official add-on for NDK support, but now you're expected to manage it with your Gradle files by hand. Now, even more than before, you're at the whim of solutions on Stack Overflow.
There's a reason AS hasn't hit 1.0 yet: it isn't ready.
[1]: http://docs.google.com/viewer?a=v&pid=sites&srcid=YW5kcm9pZC...
Second, the author points out NDK over Java as a solution which is already leveraged by some popular apis transparently from java, such as libgdx.
Finally, the ui is responsive enough. My biggest annoyance whenever I have to help my in laws or my parents with their iphones and there is no back button - I don't notice any significant difference between their iphones and my Galaxy S3, and I'm sure Samsungs phones have only gotten better.