Another year of healthy 2.5" HDDs, and the results are surprising.  The gap between 5400RPM and 7200RPM drives' performance seems to be shrinking.  However, WD manages to spank the whole class again with numbers unheard of in many 3.5" HDDs.  But getting back to 5400RPM drives, the Samsung unit did surprisingly well, and remains the ONLY 500GB drive in a 9.5mm form factor.