The truth is out. Something anyone who has used both iOS and Android, independently or together (as do I), will be well aware and very familiar with. Android UI lags, always has done, and seemingly always will do if Google do nothing about it. It seems, though, that the decision to actually do something is not as simple as it may seem.

An ex-Google insider has dished out the story on AppleInsider which some may say is mere propaganda. But if you take the time, effort and honesty to assess Android against iOS you will see that what is described is very apparent. Even with top of the range, latest technology, devices the effect is there. It was only this morning while reading a long article on the Samsung Galaxy Nexus browser that the UI lag was annoyingly apparent and consistent just performing simple scrolling down the article. There was a completely noticeable lag between moving my finger and the page starting to scroll along with it. Annoying, yes. More so now that I know the reasons why.

A former intern for Google's Android team has provided explanations for why Android experiences more touch interface lag than competing mobile operating systems from Apple, Microsoft and Research in Motion.

Source:http://www.appleinsider.com/articles..._than_ios.html
Now, as always, one should not necessarily trust a single source, and so it is worth reading the author's original notes and observations on Google

Follow up to “Android graphics true facts”, or The Reason Android is Laggy

Yesterday +Dianne Hackborn posted to Google+ an article that dismissed the common accusation that Android is laggy because UI rendering wasn’t hardware accelerated until Honeycomb:

https://plus.google.com/105051985738...ts/2FXDCz8x93s

It’s an insightful post that illuminates many of the complex issues with smooth Android rendering. Unfortunately, it doesn’t answer the fundamental question asked by both technical and nontechnical android users:

Why is Android laggy, while iOS, Windows Phone 7, QNX, and WebOS are fluid?

This post will attempt to answer that question.

Source: https://plus.google.com/100838276097...ts/VDkV9XaJRGS
He then goes on to close that particular article with:
Edit: +Dianne Hackborn has written a response to this post. She clarifies things about Android that I got wrong, and fundamentally rejects the thesis of this post by suggesting that the increased security and flexibility of the Android platform over iOS is a cause of performance overhead and that increasingly fast hardware will help resolve the issue:

https://plus.google.com/105051985738...ts/XAZ4CeVP6DC

It would be wise to trust her word over mine, as she is the final word on Android framework issues.
In my experience, then, even the current Samsung Galaxy Nexus with its Tegra 2 Dual Core processor is not fast enough hardware. Gosh, this is taking on the spectre of Microsoft Windows. But lets continue ...

Linking to the post from Dianne Hackborn (https://plus.google.com/105051985738...ts/XAZ4CeVP6DC )we find that she has a lot to say on the subject, to debunk the assertions and claims of the original author. She is, by his own words, an authority on the matter and so should be believed over him. But in Dianne's own words there are issues, regardless of any pedantry as to how they occur, and why. Simply put, they do exist, and that is the experience that the man in the street will have on Android that he will not in iOS, as unpalatable as that may be to Android fanbois (those irrationals that exist in all "camps").

Dianne maintains her credibility where she admits to her own errors, which I greatly respect:
It has been pointed out to me that iOS does in fact use multiple windows and multiple GL contexts. Lesson to me, just don't talk about anything I haven't directly verified.
Then, later, in the comments a correspondent asks:
Tau-Mu Yi - Thank you for your detailed explanations Dianne, but that still leaves the question of why is the Android UI laggy compared to iOS. Is it a fundamental design issue (tradeoff) or is it an implementation issue (i.e. further refinement of Android will fix the problem)?

I but whenever I go to the Apple store, I am amazed at how smooth and fast the iPhone UI is.
To which Dianne answers:
Dianne Hackborn - +Tau-Mu Yi There is no simple answer that you seem to be looking for. In fact the question isn't even as simple as you are asking, because you need to specify for what particular part of the UI and what is going on at that point in both systems.
And so on ...

Conclusions
As I read through the articles and the correspondent's feedback and questions I found a mental synergy with my own direct experience of Android. Since version 1.0 running on the G1, UI lag has been a constant, no matter what, as the hardware and OS versions matured over the three short years of Android's existence.

Mirrored against the iOS devices that I have owned in parallel with Android the experience there [in iOS] has been one of an incredibly smooth UI, with the exception of one or two versions that were subsequently patched successfully in later point releases.

The UI lag is an annoyance, or at best an irritation, more than anything. Some people I speak with do not even notice it, they are completely unaware. But to those who do perceive the UI lag it is bothersome but not preventative in using Android on a daily basis as intended.

Clearly, the hardware will advance, we are already on the cusp of seeing the first Tegra 3 quad-core devices in 2012. More cores, larger memories, more powerful GPUs and faster clock-speeds will all contribute to [eventually] making this a non-issue, one hopes and expects.

But for now, those of us with even the latest and greatest hardware will simply have to put up with Android's UI lag.