I got to tell ya, Since installing 4.1 last night and running Sig Test , so far so good , even better then 3gs.... Odd thing is , Apple May have been right about the misrepresentation of Sig bars and the error in formula, Before 4.1 I could hold it for about 2 min and would get no bars and Edge on bottom left ( Don't see why thats a issue anyway , unless you trying to do it to prove after a couple min the sig drops...) I have yet even with iOS 4 had a dropped call so is it possible this is much to do about nothing and a small portion of users that a hell bent on having a problem no matter what the solution is?
Who knows, My iPhone 4 works great, believe me if it didn't it would have went back, this update Beta 4.1 seems to have fixed the issue....