My experience so far is that the fan has not come on except during gaming (and initial setup/indexing). It was quite loud when it did come on.
M3 WEI.... Scale 1-9.9 (Posted to wrong response someone was asking M3 performance)
The Windows Experience is still there--even in build 9860. However, the GUI was retired with Windows 8. If you want to run the experience, which is really called the "Windows System Assessment Tool," you must run it from the command line..
Type winsat formal -v -xml c:\winstatresults.xml
My M3 (Fanless)...
</SystemEnvironment>
-<WinSPR>
<SystemScore>5.6</SystemScore>
<MemoryScore>5.9</MemoryScore>
Physical memory available to the OS is less than 4.0GB-64MB on a 64-bit OS : limit mem score to 5.9
<CpuScore>7.1</CpuScore>
<CPUSubAggScore>7.1</CPUSubAggScore>
<VideoEncodeScore>7.1</VideoEncodeScore>
<GraphicsScore>5.6</GraphicsScore>
<Dx9SubScore>9.9</Dx9SubScore>
<Dx10SubScore>9.9</Dx10SubScore>
<GamingScore>9.9</GamingScore>