iphone 5 wont have the death grip issue but it wont get as good reception as the iphone 4. Thats the tradeoff, antenna exposed so you can get great signal most of the time in more places, or old school antenna so you can get mediocre signal all the time, even when holding it like a dork
It's a myth that an external antenna like the one on the iPhone 4 is superior to a well designed internal antenna. I've owned over thirty different phones over the last four years. Needless to say they've each had different antenna arrangements. Many of these have performed flawlessly as a phone. It's not rocket science.*
Thursday morning I bought a new Droid X. It has an internal antenna that performs extremely well. I could not be happier.*