I just updated to 4.8 and I found that the update took the ability to switch between power management profiles at will.

Is there any way to get the old behavior back? I sometimes need max performance, even when I'm working on battery only.

See e.g. http://drfav.wordpress.com/2011/10/02/f ... ts-future/ and http://drfav.wordpress.com/2011/10/04/p ... creencast/.

In short: your "power profile" now depends on your current activity.