Ok have it installed on iPhone 4 on o2 in the UK. As predicted the signal strength is bolder but my non sweaty hands make the signal go right down so I'm guessing something is going to have to happen by way of product recall or apple retail store fix as the death grip is still 100% there. Sorry to be another bearer of bad news.
As I was expecting...
This isn't a software issue... the software issue just fixes minor things... not major things that clearly sticks closely to the design and hardware.