Several people have pointed out that the Verizon version of the iPhone 4 suffers from the same antenna issue we saw on the AT&T iPhone 4, but Consumer Reports did some scientific testing to prove the issue in its lab.
The Verizon iPhone 4 has a redesigned antenna layout, but it’s still recommended to use a case for best results. Using any case, such as the iPhone bumper case all but eliminates the signal issues Consumer Reports documented.
Consumer Reports performed its tests in a controlled lab shielded from other radio signals. You can read more about the tests over at the Consumer Reports Blog.