I've had problems--just nothing I'm not used to. Mostly, I can't stand the keyboard lag when I go to websites like livejournal.com or forums like this one and I try to type--in portrait or landscape mode--and there are those times when the keyboard lags on me, even after I've emptied out my cache/history. (I don't like emptying cookies because I've got some passwords that I don't like having to re-enter via the iPhone...it's a bit of a hassle.) Overall, though, I haven't had any problems, and I still think the iPhone is awesome.
Anyway--at least one person's pointed out something along these lines...that people who will speak up at all are in the minority and the huge bulk of people who buy iPhones (or Blackberrys or Sidekicks or other devices in general) won't speak up online at all. They'll go away and use the devices. Most people WILL like their devices and will be very pleased, though they won't try to change or mod their devices, either. The people who speak up at all online are generally the ones who have anything negative to say, unfounded or not. So the trolls, the haters, the folks who bought the devices because of the price tag and/or any prestige or popularity associated with them but don't know how to use them and/or don't care to know how to use them, the folks who bought the devices because they genuinely wanted them and just had plain bad luck with them...those people are more likely to say anything. And people who have anything positive to say are less likely to speak up--just because they're that satisfied, surprisingly enough, and because they don't see a need to say anything if they're happy with what they've got. In many of these device-related forums, it's not long before a thread or two just like this one will appear: "I haven't had any problems with this device! Am I the only one?" and people will speak up and provide that glimmer of hope that the device isn't as bad as the rest of the forum might imply it is.
If there's anything I've learned as a gadget freak, it's this...these devices aren't as consistently, horribly awful as people in forums like this one will claim they are. If they honestly were, the whole world would've known about it by now--it'd be all over the news. There'd be recalls of the product and they wouldn't be for sale till they've resolved the problem(s). Yeah, there are products that have slipped through the cracks, but not many--most of these companies get burned right away when they put out an honestly sub-par product. As for forums like this one...yeah, they're definitely useful. But they can be a bit of a double-edged sword, too. If you're doing research on a particular product, you have to know how to pick through the BS to figure out the truth about that item. Usually, cross-checking with sites like cnet.com, or gizmodo, or pcworld, etc, helps with figuring out what's true and what's not.