Try using a galaxy s3. The lag will be worse than with an iPhone 3GS if you are on ice cream sandwich. With jelly bean it will probably lag as much as ios6 does in iPhone 4 if that is possible.
iPhones are the smoothest, snappiest and most polished smartphones. And I personally prefer a 3.5" screen for my phone.
Galaxy s3 is better in a few respects like open source, better screen etc. but overall I would take an iPhone 4S anyday. And this comes from an owner of both and former android fan and apple hater.
Pure fantasy. It sounds like your Android experience are generalizations based on Android 2.3 hardware from 2010. Have you even used a GS3? Or an Iphone 3GS since the iOS 6.0 release?
There's no question that, given similar hardware, the iphone's OS animations are smoother. An Iphone 5 lags less than a GS3, though here we're generally talking about micro-lag of half to a quarter of a second. However, switch to old hardware and the speed advantage goes away. Yes, an Iphone 4 scrolls quickly between app pages, but actually run anything on it and it is in no way faster than a galaxy s3, even on only android 4.0 (no project butter yet). The 3GS is dog slow with iOS 6 when you actually use it.
The Iphone 4s with its dual core cpu is a marked improvement over the Iphone 4 and in terms of perceived "lagginess" yes its about on par with a gs3. But, the screen is too small for many people (myself included). It's personal preference what size phone you prefer.
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For the people who say that "a galaxy s3 is as smooth as an iPhone 3gs" - do you do anything on your phone other than scroll between app pages? Even surfing the Web on safari chugs on a 3gs. Even then, the 3GS hardware only has to drive a super low 480x320 resolution screen!
Do something like browse the Web or surf content-based Web apps on a galaxy s3 with LTE vs an iPhone 4S using hspa+ (not true 4g) and you'll notice a difference as well...
Yes apple's OS is well designed for smoothness but some of people's perceptions are clearly not based in reality.