Consumer Reports tested the Verizon iPhone 4 using the same methodology as the original GSM version, and with the same results: signal strength drops if the iPhone 4 is gripped in a certain fashion, commonly known as the "death grip." As a result of its testing, Consumer Reports decided it couldn't recommend the Verizon iPhone 4, either.
Similar testing done by AnandTech throws some cold water on Consumer Reports' findings, however. Not long after the Verizon iPhone 4's launch, AnandTech found the Verizon iPhone 4's "death grip is essentially mitigated."
The Verizon iPhone 4 experienced a signal loss of 16.5 decibels (dB) when held in "death grip," compared to signal loss of 15.5 dB when held "naturally." This is far better performance than the GSM iPhone, which experienced signal loss of 24.6 dB in "death grip" and 19.8 dB in "natural grip." In other words, the Verizon iPhone 4 in "death grip" mode experiences less signal degradation than a GSM iPhone 4 held "naturally."
AnandTech compared the two models of iPhone against eight other smartphone models, including an iPhone 3GS, a BlackBerry Torch and several Android handsets. The average signal loss for those models when held in their own version of "death grip" was 14.4 dB -- significantly less than the GSM iPhone 4, but not substantially better than the Verizon iPhone 4.
As for the "held naturally" numbers, the average signal loss among the other models was 7.4 dB compared to 15.5 dB for the Verizon iPhone 4. AnandTech notes that the average dB loss gets skewed downward because of relatively low signal degradation in the Nexus S and two Droid models; interestingly, the iPhone 3GS had by far the lowest signal degradation of any phone tested, losing just 1.9 dB when held "naturally.""I feel completely confident using the CDMA iPhone 4 without a case, and did so for the duration of all this testing without once dropping off the network," AnandTech's Brian Klug noted. The results also show that when used with a case, the Verizon iPhone 4 experiences signal loss of only 9 dB -- comparable to all other smartphone models.
It's worth noting that AnandTech was the first outlet to fully diagnose the original iPhone 4's signal attenuation problems, so its analysis is definitely reputable. Consumer Reports' findings, and its refusal to recommend its highest-rated smartphone even after the antenna issues have been addressed to the satisfaction of other research firms, are another matter.[via Fidelity]