Battery Life Is A Difficult Issue

I'm not entirely sure why this should be the case but whenever I hear complaints about the battery life of the Samsung Galaxy Nexus I'm left bewildered. Here you can see a screenshot from my own device demonstrating that after 29 hours away from a charger its just dropped below 40% charge. In my book a potential two day battery life isn't something to complain about.

Similarly with my iPhone 4S, I found that the battery was easily able to get me through a full day away from charge - despite many others complaining of extremely poor battery life.

Why is this the case? I have no idea. My Wi-Fi and Bluetooth radios are always enabled, I use Push for everything available and I use automatic brightness to manage the screen. If anything I'd expect worse than average battery performance.

Perhaps its the rigorous three charge/discharge cycles I perform when I receive a new phone. Whatever the case I'm happy for it to continue into the future...