basroil :
gondo :
I guess you never heard of www.frostytech.com
They use a reference heat plate, not a CPU and test all heatsinks side by side using the same heat source. You'll have a list of 100 heatsinks tested side by side.
Not just them, most sites that do real cooler reviews have thermally isolated testing environments with proper heat loads, default fan and preset forced convection, and acoustic testing. On the other hand, few review sites have as comprehensive a GPU power draw setup and PSU testing, so I wouldn't really rail too much on their (current) inability to properly test CPU coolers.