iPhone 4
Sharp, precise, classic. This phone will still look fantastic in ten years time. The idea to run the antenna around the edge of the device was inspired, but technically flawed. This was perfected with the 4S.
iPhone 5
An unfortunate devolution of the iPhone 4. Perhaps responding to the glass cracking epidemic. Took many of the design cues of the 4, but introduced incongruous top and bottom panels, to compensate for the lack of glass.
iPhone 3G
An evolution of the 2G design, and although many decry the plastic shell, it was Apple's first attempt to deal with the antenna issue. It was warm to hold and hands down the most ergonomically comfortable phone they've ever made. Nightmare to use on a table though. Tacky chrome bezel.
iPhone 2G
Oversize and under performing, it did at least change the world. The aluminium fit with Apple's material palette and the profile for better or worse followed the then recent white Macbook design. Had a slightly odd plastic panel at the bottom. Tacky chrome bezel.
iPhone 6
Basically a slimmed down iPhone 2G. I get the feeling this design had the same origins and has been refreshed to make it relevant. * But Apple designed themselves into a corner with the antenna bands. Coupled with the clear compromise between design team and engineers regarding the depth of the camera module and it's obvious to see that this phone was designed by committee. It's not a terrible phone by any means, just not very focused.
* To rant a bit, I imagine the design of the iPhone 6 was established soon after the passing of Jobs but I definitely don't mean to repeat that tired phrase "Steve would never have allowed this". Many of the products over the last 4 years have been evolutions of designs that were established with Jobs - Macbooks, iMacs, iPads etc. Obviously products have a huge lead-in time to develop and without Jobs in late 2011 I'm sure there was a massive hole in deciding who had the authority to direct the design future of the company. It probably took a good year to establish a really solid approach going forward, how to deal with a design team that was now working in a vacuum, no restrictions or guidance from someone with major conviction or authority.
The three headline new designs we've seen Post Jobs have been the Mac Pro, iPhone 6 and Apple Watch. The Mac Pro was clearly an early 2000s design and has obvious design cues from the G4 iMac - round base, with near identical ventilation holes at the bottom and designed with the principle that the components could be seen. slip a translucent tube on it and *boom* that's your 'G4 cube' sized product.
Similarly for the iPhone 6 I feel they cribbed an old iPhone 2G era design that may have previously got a warm reception from Jobs and retooled it for modern sizes and tech. The profile and cut at the aluminium edge to to the screen are very similar. From that concept though, clearly someone steadfastly refused to find a new antenna approach and instead relied on an identical technique to the iPhone 5. The issue being that the 5 used its edges to mitigate the change in material, but the 6 design has a completely ungainly approach that actually fights against the rounded design. That and the camera blemish suggest this design really lacked direction.
The Apple Watch could be seen as response to the 'failure' of the iPhone 6 design. Like I said, no one can design in a vacuum. You need people to push you to do better, and importantly tell you when you're going wrong, because most designers have a hard time looking truly objectively at their own work. Whether you like him or not, I think this is where Marc Newson fits in. Physically detached from the design team in Cupertino, they can establish proper design reviews with other people who really, really get design. Not just a board room full of people with big salaries. This probably works both ways too. Imagine the creativity and competition that can be fostered by two design teams on each side of the Atlantic working to make the worlds most exquisite products.
After this lull, going forward I think we will see some really exciting and crucially unexpected designs from Apple.
Massive post, sorry!