The biggest disappointment for me is the phone part of the package - it's a real shame, but the iPhone isn't actually that great at being a phone. Don't get me wrong, the call quality is excellent, with the sound from the iPhone being crystal clear, while I've had no complaints about the quality at the other end either. The problem is that the iPhone seems to have trouble holding onto a signal - it's literally a case of, one minute I have five bars, the next minute it's telling me "No Network". I've actually watched the iPhone peak and trough between full coverage and no coverage, without even being moved. I've tried various SIM cards on various networks and the issue remains. I even tried a different iPhone, in case the problem was with my handset, but still there was little improvement.
The signal strength issue is completely random, because I've managed to conduct very long conversations using my iPhone without incident, but then at other times it just randomly drops the call. There are rumours that this problem could be addressed with a firmware update, but it seems more like an antenna issue to me. Either way, the weakest link in the iPhone's armour is actually its ability to make and receive phone calls - which is a shame. But to be fair, although this can be annoying at times, it hasn't stopped me using the iPhone as my main handset for the past couple of months, so it's far from an insurmountable problem.
Continuing the list of negatives, the iPhone doesn't support MMS. So, even though you've got a built-in camera, you can't send any pictures you take to friends or family. Yes, you can email photos to people, but the lack of MMS functionality is a real letdown on what is a very media focussed phone.
Another disappointment is the Bluetooth implementation. Although the iPhone supports Bluetooth, it only allows the use of a hands-free device. Luckily, this isn't limited to Apple's overpriced Bluetooth headset, since the iPhone works perfectly with the Bluetooth setup in my car. But if you were planning to use a set of Bluetooth headphones, like the strange looking, but very good Etymotic Research ety8 wireless earphones. Basically, the iPhone doesn't support A2DP, so you simply can't use stereo Bluetooth devices - again, a very strange decision for something that's a media based product.
The lack of stereo Bluetooth support brings me nicely onto another annoyance, the headphone socket. Although the iPhone uses a standard 3.5mm headphone socket, Apple has recessed it deep into the casing, making it almost impossible to use third party headphones. For example, my Shure E500PTHs would not fit into the iPhone and I ended up having to butcher an extension cable with a knife to get it to fit.
But even taking a knife to my own property was preferable to using the bundled Apple headset that comes in the box. Thankfully Shure has solved this problem for me by releasing its Music Phone Adapter. Not only does this have a slim plug to fit the iPhone, but it also has an inline microphone and will accept any headphones. I'll be writing a full review of this very soon, but suffice to say it's a must have item for any iPhone user.