As a Ph.D EE with more than 20 years of experience in the area, I believe consumer report's tests is more reasonable and the conclusion is more scientific. IPHONE4 does has a design fraud.. At a relative high frequency, When user touch the antenna, in particular, if there is a small gap between two poles of the antenna as designed by the Iphone4 , touching the gap can cause the Impedance change easily, causing mismatch of a network system (antenna network system). this will cause the signal drop significantly for sure!
Apple's claim that the IPHONE4's signal problem was due to a software bug is a cover up, it is a joke!
more than 80 percent of the people use bumper cover and they dont have any problems, and I dont think you dont need Ph.D for that. Nobody is returning iPhone 4 with antenna issue rumors, so do your research Ph.D, dig a little deep.