that's unfortunate, because I don't have the death grip issue, even if I hold it on the death grip, I don't lose signals at all, like I can not get the bars to go down, even if I hold it very tightly it does not go down at all. Ever since I got my iphone 4 in August, I have not dropped a single call, ALL of my calls went through just fine, no dropped calls, no receptions lost, no failed calls either. This is with the case and I have done with without the case and still working normally fine.
If reception is an issue for you, Apple does offer a free case program that you can download on your iphone 4. But keep in mind that the free case order only works within your 30 days of purchase, if you are past the 30 days, it won't work.