With WWDC 2009 just around the corner, and write a review of iPhone 3G on my TODO list, if I don't write something this week then it'll be outdated before I even write this. So without further ado, the highly belated iPhone 3G review ...

Having first purchased an original iPhone (for use unlocked on Orange), the changes between the iPhone and iPhone 3G are both noticeable and gave me an opportunity to test them side-by-side. The differences are both cosmetic, functional and not always an upgrade.

In what looks like a continuing trend, the iPhone 3G's shape is subtly different from the former. Whilst the former version had a flat back, the newer has a rounded back. This results in thinner edges but a fatter middle. Opinion is divided on what 'feels' better, but undoubtably the feel of the full-metal back versus tacky plastic back is noticeable either way around. The iPhone 3G thus ends up feeling cheaper, if not slightly more comfortable, to hold. A cycnic might observe that it is also an excuse for Apple to sell more docks, since the newer model doesn't fit the older docks without the use of some kind of Dremmel tool to file it down.

The speaker/microphone is also different – not necessarily in a good way – between the models. The original has a set of tightly drilled spaces into the casing (which mated up into equivalently positioned spaces in the dock) whereas the latter has a bigger case incision and a wire mesh internally. The end result is that you can end up with more fluff buildup into the new iPhone 3G speaker/microphone holes than the original generation. Aesthetically, they don't look as good either. Perhaps the reason was to support better speakerphone operation (which the first didn't have at first; though a software upgrade might have added later).

The rounded back also has its problems with working flat on a desk. The old model was sturdy and you could type on it flat; the new model really doesn't work when flat on a desk if you want to press buttons. About the only good thing you can say about the back is that the bluetooth signal, when horizontal, was absolutely pants with the old iPhone model (due to interference with the metal casing). It works fine if held in portrait mode, but clipped to a belt in landscape mode made the bluetooth headset drop out much of the time. The newer iPhone 3G, due to its lack of metal back, doesn't have this problem. So it's good that the newer model (allegedly) will have a matt or rubberised back; not metal, but not cheap plastic either. We shall see.

The screen of the newer model is decidedly jaundiced, with a yellow tint obvious when holding up the two models next to each other. Although not obvious if you've only ever held one, the colour reproduction on the first model was much closer to reality than what's shown on the iPhone 3G. I suspect an original manufacturing fault turned into a marketing ploy, and it wouldn't surprise me if the new iPhone will have a slightly cooler tint with some kind of marketing gumph like "Now more accurate colours!" thrown into the StevePhilnote.

What about the other new features of the iPhone 3G? Well, the GPS is really handy. You wouldn't leave it on all the time (at least, you wouldn't unless you had a charger with you at all times) but for the periods in which you want to use it, it works great. Rambling off the beaten track, it'll tell you where you are in the world, and even if you're off the (Milton Keynes) grid, you can still use satellite maps to find out where you are and where to go. Clearly this is useful as long as you have a mobile signal, but apps exist which can track your path even in the absence of an internet connection to download maps. In addition, the iPhone's GPS combined with (lackluster) camera brought geotagged photos to a wider audience than previously, and indirectly ensured that iPhoto support for geotagged photos wasn't far behind. Whether the new iPhone will get a magnetometer for using as a compass direction is an interesting idea; it's got much less use than the GPS has, but perhaps could be used in conjunction with the location services to extend the accuracy of the GPS, but you could also imagine treasure-hunt applications that take your location into advantage with your direction “take five steps North ...”

Lastly, the all-new 3G part of the iPhone 3G. Maybe other experiences from elsewhere in the world differ, but in the UK with O2, the 3G is a complete waste of time and battery power. Yes, the 3G is faster than 2G when you're outside or standing next to a transmitting tower. However, inside buildings, paper bags, or even pockets, the 3G signal is patchy. There have even been instances where telephone operators have installed in-building repeaters in order to maintain 3G signalling in key locations (read: important customers). For me, if I used 3G, the signal was so weak that it ping-ponged back and forth between 3G and 2G. Worse, if I had an incoming call but 3G was one bar, then the network just routed it straight through to voicemail even though I allegedly had a 3G connection and it was on in front of me. Lastly, and this is probably a benefit to me due to the location that I work, the WiFi connectivity around here is pretty comprehensive - I can walk into a Pret, Starbucks or even the cloud and get a WiFi signal which is faster and lower battery consumption than a 3G network is. Even the train I'm typing on has a WiFi network on it. When I'm outside WiFi range, the 2G signal is acceptable; and it has the added advantage of being able to receive/make phone calls. Given that my iPhone is, well, a phone first (and a PDA second/web browser third) being able to use it as a phone is a higher priority than the 3G network utilisation. Partially, this is a problem with the O2 3G network (combined with working in a densely populated city where the signals block 3G and living in a more sparsely populated city where the 3G towers are way off in the distance) but given the inherent problems, I turned off 3G almost as soon as I got the phone and didn't look back. (Settings > General > Network > Enable 3G if you want to do the same.) So, even if the new version of the iPhone has HSPDA downlinks, I think the network support is likely to be as good (bad?) as it currently is, and therefore on its own, not a big leap.

Niggles aside, the iPhone and iPhone 3G are still the best phones I've used, and the ability to run applications (whether a twatter client, games or even my own creations) means that even at home, my iPhone probably gets more use as a sofa-browser than any other device I've owned before. The new iPhone can't really go wrong, and whilst minor updates (memory, processor, HSPDA) are pretty much guaranteed, the phone will still be much the same phone as before. iPhone OS 3.0, likely to be released at the same time the new iPhone will be later in the year, will add some missing features like cut'n'paste. But even without c'n'p, the iPhone is still a great platform and telecommunications device.