If the norm is even higher, then the increase is less as a percentage, but no wonder ATT won't release the numbers.
I live in Los Angeles. There are cell towers uglifying the sky everywhere. My favorites are the mock trees -- one in Burbank is a squat, fake palm tree with "coconut" repeaters. And despite the apparent ability to put towers absolutely anywhere... AT&T still blows.
My family and friends have similar issues. A couple don't have it so bad because they're on the West Side, where AT&T seems to have built more towers -- gotta keep Beverly Hills & the movie studios happy, you know.
Oddly, we have little trouble with 3G data. I can stream podcasts and use Google maps simultaneously. It's the calls that are the issue.
But I have to wonder if this problem is exaggerated by the 3G connection maintained by the phone. My dad used to have the same problem in NY (not the city), but he switched to edge and stopped dropping the calls. He just turns on 3G when he knows he wants to do some faster web browsing, which is rarely for him. Maybe you could try turning off your 3G and see if it reduces your problem in LA?
Yes, I was shocked. I thought Apple handled this all well, but I was really expecting them to say that the "iPhone 4 still provides better reception than the 3GS". I guess they can't actually make that claim and I still find that a bit funny.
The measurement provided was simply the "drop rate" per 100 calls. Implicit in this is that it's the drop rate for successfully connected calls, since a call that never connects can't be dropped. I believe that the iPhone 4 is more sensitive and has better reception than the 3GS. There are rooms in my house where I get 0 bars and I can't make a phone call on the 3GS but I can successfully make calls on the iPhone 4.
So let's say I try to make 100 calls, but the reception sucks in some rooms so on the 3GS only 80 calls successfully connect and of those 4 get dropped. That's a drop percentage of 5% or 5 our of 100. But let's say on the iPhone 4 I'm able to successfully connect on all 100 calls, but since the signal is so low in some of the rooms, I drop 10 of the calls. So 10% or 10 out of 100.
So I've now got a drop rate that's double the 3GS, even though I'm able to make 10 more completely successful calls per 100.