Verizon iPhone 4 also has antenna issues
In the course of conducting its standard suite of iPhone 4 performance tests, iLounge discovered the phone can lose substantial cellular signal strength when held in the prior "death grip" position, as well as Wi-Fi signal when held in a different "death hug" position. In both cases, data reception is either noticeably slowed or completely stalled. A video demonstration shows the findings:
Thankfully, the issues can be fixed in the same way as with the GSM version of the iPhone 4: buy a case. Keep that in mind if you're planning to purchase an iPhone 4 from Verizon. Alternatively, you can just wait till this summer, when the iPhone 5 will likely arrive.
Source: http://www.techspot.com/news/42343-verizon-iphone-4-also-has-antenna-issues.html