OK - my own experiences; I make no claim that they apply to anybody but me.
I'm in the UK on O2 and have historically had good signal on my 3G nearly everywhere I went. No dropped calls (apart from the obvious cases such as going into tunnels).
Then iOS 4 came out. My 3G started randomly jumping from 5 bars to 0, full 3G connectivity to GRPS only, whilst standing in the same place. It looked like the phone was randomly switching towers, but it's hard to be certain of that. When I once had strong signal throughout my house, I now have to stand near a window to get it. The same problem occurred with the iPhone 4. To me, this looks like a problem with iOS4, possibly the "jump to the least busy tower, rather than the nearest" change mentioned earlier in the thread. This is a big issue, as it causes both my 3G and my 4 to drop calls repeatedly and lose data connection. However, since it seems to be related to iOS 4, I presume it can be fixed in software.
I've also experienced the "death grip" problem on the iPhone 4 only. I noticed this before it was publicised, because it was so obvious. A bumper fixes this problem, but not the one I described in the previous paragraph.
My suspicion is that 90% of the problems are caused by the tower-switching, with 10% caused by the new antenna. If that conclusion is correct, there's a fair chance it could be fixed with a reversion to the previous tower-selection algorithm. However, that would require the agreement of Apple's carrier partners (such as AT&T). It would probably take longer to get this than change the software, which is why there may be a delay in announcing the fix.
If there's one thing that's more embarrassing than fouling up a new antenna design, it's being found to have deliberately degraded your phone's performance in collusion with the carrier.
I'm in the UK on O2 and have historically had good signal on my 3G nearly everywhere I went. No dropped calls (apart from the obvious cases such as going into tunnels).
Then iOS 4 came out. My 3G started randomly jumping from 5 bars to 0, full 3G connectivity to GRPS only, whilst standing in the same place. It looked like the phone was randomly switching towers, but it's hard to be certain of that. When I once had strong signal throughout my house, I now have to stand near a window to get it. The same problem occurred with the iPhone 4. To me, this looks like a problem with iOS4, possibly the "jump to the least busy tower, rather than the nearest" change mentioned earlier in the thread. This is a big issue, as it causes both my 3G and my 4 to drop calls repeatedly and lose data connection. However, since it seems to be related to iOS 4, I presume it can be fixed in software.
I've also experienced the "death grip" problem on the iPhone 4 only. I noticed this before it was publicised, because it was so obvious. A bumper fixes this problem, but not the one I described in the previous paragraph.
My suspicion is that 90% of the problems are caused by the tower-switching, with 10% caused by the new antenna. If that conclusion is correct, there's a fair chance it could be fixed with a reversion to the previous tower-selection algorithm. However, that would require the agreement of Apple's carrier partners (such as AT&T). It would probably take longer to get this than change the software, which is why there may be a delay in announcing the fix.
If there's one thing that's more embarrassing than fouling up a new antenna design, it's being found to have deliberately degraded your phone's performance in collusion with the carrier.