It's the debate that refuses to go away, but at the same time, doesn't seem to be doing much harm to sales. Yes, we're talking iPhone 4 'death grip', with tests carried out by the PA Consulting Group now indicating that the iPhone 4 does suffer from connectivity problems compared to other smartphones on the market.In the majority of the tests, PA's wireless technologists found the iPhone 4’s performance was in the same range as the other smartphones tested (Blackberry 9700 and HTC HD2), but at the lower end of that range. But when the 'death grip' was used, the iPhone 4's performance became 'significantly worse'.According to Simon Tonks, the consultant who led the testing: 'Our tests indicate that the 'death grip' issue is real, and is worse for the Apple iPhone 4 than for other smartphones. The iPhone 4's radio performance was also found to be generally at the lower end. This means it will tend to drop calls earlier than other phones and may suffer more in areas of weak signal. Though, overall it's still within the normal performance range for similar products.'Dr Phil White, head of the wireless technology team at PA added: 'Consumers always prefer products that look and feel good. And we all benefit from the way companies like Apple are prepared to take risks and push the boundaries of product design. But that means striking a balance between incorporating the most innovative features and ensuring the product works effectively. The trick lies in finding the right trade-off. The question is whether consumers are prepared to put up with occasional performance flaws given the additional benefits more innovative products provide.'If words are not enough, you can see a video of PA's smartphone testing here.