Funnily enough I have/had 4 iPhone 4s in our household – none of them suffered from the death grip adversely – sure if you held them as tight as you can in both hands the signal would drop – but which phone doesn’t, and do you really make calls like that?
I’ve been asked a few times about android or apple, I look after an Apple office, we’ve got MacBook Air’s, servers, iPads and iPhones, I have an iPhone 4 & an Android (Xperia S) and my answer to those questions is this.. Do you want to take it out of the box and just use it without playing around trying lots of different apps to find one that does work, but only get to 95% of what you want? Then get an Apple device… If you’re happy to waste days tweeking and testing but want it exactly how you want then Android…
I’m using the Xperia S mainly these days but only becuase of the bigger display – 4″ iPhone 5 will see me back to Apple.