The reason that there is only one iPhone release a year. So it better be much faster than the competition at release so as not to get totally whopped 4 to 6 months down the line. iPhone 4S sales started softening in the 3rd quarter itself instead of the usual 4th quarter before the new iPhone comes out.
iOS devices have never really been on top for CPU benchmarks though have they?
For example the Tegra 2 based non-prime Transformer and A5 based iPad 2 were released about the same time (March 2011) and that Transformer score 35% higher on Geekbench but the A5 GPU benchmarks were way way ahead and have stayed competitive with today's competition [1].
"so as not to get totally whopped 4 to 6 months down the line. iPhone 4S sales started softening in the 3rd quarter itself instead of the usual 4th quarter..."
Does anyone really think that iphone sales lagged more than previously because of CPU benchmarks?
I would guess only indirectly as better performance on Android has helped make the experience better. But there's all kinds of other things improving the Android experience (e.g. better apps, better content experience, ICS and Jellybean hitting more devices).
Even with Android improving relative to iOS over the year I'd say a more reasonable reason for Apple's Q3 lag was the fact that they rolled out globally in 2 quarters instead of, historically, adding more countries and carriers well into Q3 and sometimes Q4 of launch. The iphone 4 also had the midseason CDMA and the much delayed white iphone launches midyear.
