Below are the idle results for the different conditions.
These results show there is no longer a huge power savings from using PowerTop on the Intel notebook and netbook that were tested, but there is some benefit. The ThinkPad T60 with its Core Duo processor shaved off just 0.578 Watts or about 4% when following the PowerTop recommendations. The Samsung NC10 netbook had cutdown its power consumption by 0.803 Watts or about 6%. Of course, if your hardware does not support WiFi power savings or you use your Bluetooth interface actively along with USB peripherals, there will not be much at all in the way of savings.
When looking at the power savings when under the OpenArena-GraphicsMagick-PostMark workload, there was not any greater power savings via following PowerTop's recommendations when the systems were stressed. The ThinkPad T60 again just went through about 0.5 Watts less power and the Atom netbook cut down its power consumption by 0.8 Watts.
While using PowerTop in 2010 may not lead to significant power savings like it has done in the past for us -- though the Atom netbook's battery life would still be extended by about 6% -- it's good in the respect that more of the power performance optimizations for Intel hardware have worked their way into the mainline Linux kernel and related components. All that PowerTop v1.11 basically did for us was to disable the Bluetooth as it wasn't being used at the time, enabling USB auto-suspend, enabling WiFi power-savings, and enabling power-savings for the Intel HD audio. If you are serious about extending the battery life for your Intel mobile device, PowerTop still may be worth trying out. It is also worth noting though that Intel is not too actively developing PowerTop anymore, but as aforementioned, its last release was 18 months ago and even in its Git repository the only work in the past few months have been translation updates. In fact, there have not been any major code changes to PowerTop at all this year.