Calipers and CR to the Rescue in Thickness-Gate
Meanwhile, Phil Schiller, in a direct message on Twitter, told an end user the two versions were the exact same size.
Consumer Reports, while loving the iPhone 4, hasn't "recommended" it because of its Antenna-gate issues. In terms of Thickness-gate, though, they came to the rescue with a set of calipers. According to their measurements, both were 0.37 inches in thickness, or 9.398mm. That's slightly thicker than the advertised specs of 9.3mm, but they were, at least, the same thickness.
So why did others earlier reports note a definite size difference, enough so that it could be felt in a user's hand? Manufacturing tolerances could be an answer, but 0.2 mm on a 9.3mm device could keep a case from fitting. BGR went so far as to note Apple's "increasingly poor quality control."