When you compare any of the newer competing smartphones to an iPhone 3GS, you see what a difference resolution makes. For instance, the Motorolla Droid has a 854×480 display that is 3.7″ (diagonally). That gives it a pixel density of 265ppi compared to the iPhone 3GS density of 163ppi. The new iPhone 4 has a density of 326ppi, which is better than the Droid and significantly better than the previous iPhones. If you were to shrink the Droid display to the same size as the iPhone 4 display, it would have a pixel density of 280ppi—just 20ppi below what Steve Jobs says is the limit of perception. You can see what a huge difference pixel density makes in a previous post comparing the Nexus One display to the iPhone display.

The new display is also an IPS LCD, which gives it much better viewing angles than a traditional LCD; however, the contrast ratio is not amazing at just 800:1. That’s a huge step up from previous iPhones, but the Droid’s contrast ratio is 1400:1 and the Nexus One is 65,000:1 (source), meaning that the contrast ratio is likely to impress you if you’re using a current iPhone but not if you’re using one of many other leading smartphones. The “retina display” appeared darker than the iPhone 3GS, but we’ll have to wait to see if that’s really the case or just an issue with the demonstration setup.

Video Calls
Another big feature that was shown off is the ability to make video calls. For some people, this will be huge, but keep in mind that the iPhone 4 can currently only talk to other iPhone 4 devices and only if they are both on WiFi. This is a very different approach than was taken by the Evo 4G (which uses Qik), but the WiFi limitation is probably for the better considering the problems users have reported with AT&T’s network.

AT&T
Speaking of AT&T, they have made some notable changes to billing recently. The good news is that people who were eligible to upgrade an iPhone this year are immediately eligible to upgrade to the iPhone 4. The mixed news is that the monthly data plans are now $15 for 200mb and $25 for 2gb. There is no unlimited plan for iPhones, and tethering is going to be an additional $20 a month. If you’re a light data user, this is great news because you can pay less and it should lower the stress on AT&T’s network. If you’re somehow actually using 2gb a month, the news is not so good. Plus, the overage fees are distributed in “buckets” too. If you go over your 200mb allotment one month by even a single byte, you’ll be paying double for your data fee ($30) and you’ll get another 200mb. And, finally, the bad news: A new smartphone contract comes with a $325 termination fee. Meaning that even after the pro-rated change, you’ll still pay close to $100 to terminate your contract just one month early. I expect to see the FCC look into this, but who knows if anything will actually come out of it.

Design
The iPhone 4 is in the new case revealed by Gizmodo. It’s 24% thinner than the iPhone 3GS and even a half millimeter thinner than the Samsung Galaxy S. Some people love the design; some people hate the design; some people think it looks like a Vizio TV (I tend to agree, but Apple products have commonly borrowed design from other sources). The design is all about functionality and squeezing as much hardware in as little space as possible. It’s been some time since the Gizmodo leak, and in that time it has grown on me as a very industrial, function-over-form design. I definitely don’t consider it good-looking, but it’s not ugly either.

Other Improvements
The new camera sensor is significantly improved and has an LED flash. The pixel quantity (5mp) is nothing to get excited about, but the quality Apple is claiming is extremely impressive. We’ll have to wait until this is in real-world conditions to see how it really performs though, particularly in low-light conditions. It is also capable of 720p video at 30fps, which is very good for a cellphone (though, again, we’ll have to wait to see the quality). The strange thing is that, according to Apple’s specs, the iPhone is capable of outputting video at

1024 by 768 pixels with Dock Connector to VGA Adapter; 576p and 480p with Apple Component AV Cable; 576i and 480i with Apple Composite AV Cable (cables sold separately)

This suggests that there is currently no way to directly output the 720p video to a TV. I’m wondering if this is an actual limitation of the phone, the connector, or simply a site typo.

The iPhone 4 has a noise-cancelation mic, which is strangely at the top of the device rather than the rear. The phone now has an A4 processor similar to what is used in the iPad, which should give excellent performance for standard apps, but I’m curious to see OpenGL performance. The battery is slightly larger and is claimed to have better life. Unfortunately, battery life is another spec that requires some real-world testing. The phone now has a gyro, which should give better motion sensing (presumably for games because the accelerometer already seemed good).

Conclusion
Overall, the hardware is really solid, and I expect it to have a very good, quality feel. This is a huge leap ahead of the previous iPhone, but this revamp puts the iPhone 4 very near to other leading smartphones. The biggest problem is that this isn’t a major leap ahead of other smartphones, and now they have an entire year of improvements before the next iPhone comes out. For current iPhone users whose devices do everything or nearly everything they want, this will be an excellent upgrade, but I don’t expect many Android-leaning people to be swayed.

I checked at an ATT store in person because I thought I could make a deal. I owe them less than half of my contract, so maybe I could get the iPhone for half the difference ($300), but they wouldn’t do that. Interestingly enough, the contract breakage fee is $175 (not sure if you can do this but it would actually be cheaper to break the contract and sign as a new customer than to re-sign as an existing customer!). They don’t want to give me a deal for $300 and have me go from a $45 monthly payment to a $75+ monthly payment. Instead, they want to wait until the last moment to offer me a deal, hoping that I’m really impatient. Of course, at that time other carriers might be looking a lot more appetizing. More Android devices are coming out, and the Pre will probably be pretty cheap with its sibling, the Pixi, coming out. Plus, data plans are cheaper with other carriers such as T-Mobile.

What ever happened to rewarding customer loyalty?