Consumer reports “RF” engineers should know better than to think they can run an engineering grade test for an issue like this in a shielded room. And certainly not one with people in it.
To even reasonably run a scientific test, the iPhone should have been sitting on a non-metallic pedestal inside an anechoic chamber. The base station simulator should have been also sitting outside the chamber and had a calibrated antenna plumbed to it from inside the chamber.
The merits of Consumer Reports’ testing methods aside, there’s no denying that many users are witnessing signal degradation depending on how they hold their iPhone 4. At the same time, I gripped an old Sanyo phone of mine, and sure enough, saw the number of bars drop immediately. I wonder what percentage of iPhone 4 users would have noticed a drop in call quality or in frequency of dropped calls but for the little game you can play with your finger and the iPhone.