I just got back from the Apple store to grab my 2011 MBP 13". Here's what the guy explained to me in a nutshell about the battery: -It's the SAME BATTERY as the 2010. -When the 2010 battery was tested, they had all the settings and running programs low. The brightness was set at under 50%, for example. The 2011s, they had all the settings higher, and had the brightness at 50%. -And the obvious: Faster, more powerful processor + same battery as 2010 = battery won't last as long as the 2010s. So the battery did NOT get "worse." Hope this helps.