IOS – iPhone 3g; iOS 4.2 to iOS 5 performance

Having used 4.2 GM on my iPhone 4 for a couple of weeks now I personally find it much much better at managing and minimising memory usage (regular checks using iStat). This should translate to better performance on older devices with limited RAM as less RAM to flash swapping will be required.

From the iLounge article

Thus far iOS 4.2 appears to perform as well as iOS 4.1 did under similar conditions. Performance even on older devices such as the iPhone 3G is the same as iOS 4.1 and thus far we haven’t observed any significant changes in battery life.