First off, battery life is very good, particularly when compared to its predecessor (the 3GS, which I often had to charge at least once, sometimes twice, per day). But depending on usage, my iPhone 4 can last into the next day, which is a huge boon for people who don’t fancy adding chargers and portable power packs to their baggage. I’ve had almost seven hours of talk time on this, but only 4.5 on the 3GS before the “20% battery left” nagging starts.
There are two reasons for the enhanced longevity: The larger, higher capacity battery and the A4 processor chip. The iPhone 4 has the same chip as the iPad, which has already been glorified for its battery life. What Apple’s proprietary processor also brings to the party is a faster speed and performance boost, which is reportedly on par with other 1Ghz smartphones, like Snapdragon-equipped devices. In my case, I definitely found this to be true. The i4 also packs more RAM, at 512MB, which further enhances speed and performance.
The iPhone 4 supports 720p H.264 videos and JPEG vid playback. That’s a big bump, considering the 3GS can only handle 640x480. (Note that MPEG-4 vids, however, are still capped at 640x480.) This means HD flicks can play on the iPhone 4, and the detail is noticeable on this screen. You can also play unconverted AVI-formatted M-JPEG HD videos from certain cameras (like newer Nikons), though not all HD vids will work without converting them. But even this isn’t too big of a deal, since there are free and paid converter tools that make easy work of this. (In fact, using one called Handbrake, I converted a vid, imported it to iTunes and now subject my poor friends to watching my vacation video on my iPhone.)
As for streaming video, it starts quickly and runs without hiccups or even much buffering when I’m in a strong 3G area. In all honesty, though, the YouTube app over 3G has always looked pretty nasty on every iPhone, even worse than low-res, and it’s no exception on the iPhone 4. This was done on purpose, probably to spare the data bandwidth. But this isn’t a hardware limitation. The device is more than capable of playing streamed video beautifully. Over Wifi, it defaults to HD vid, and offers stunning resolution. (Side note: YouTube now has a mobile web version using HTML 5 that allows direct streaming from the site. Using this, vids run both via 3G and Wifi in HD — making it well worth ditching that built-in YT app, IMO.)
To give you an idea, I took some screen captures of the "Moon" cinema trailer, starring Sam Rockwell, as it streams on iPhone 4 via 3G. Top to bottom: YouTube app, YouTube's mobile site (standard res) and YouTube's mobile site ("HQ" version).
Above, YouTube app over 3G: About as clear as Lindsay Lohan's blood alcohol level after a party... Ick. Below, YouTube mobile site, streaming a standard def vid over 3G: Better, but not terrific. But the bottom one? ...
Bottom, YouTube mobile site streaming HQ quality vid over 3G: This is glorious!
I'm going to talk about Wifi for a moment. In short, most hotspots and home routers these days broadcast in 802.11 B/G. 802.11 N is the next generation up, and most of the industry is/will be moving toward it. This means any handset that supports it — including the iPhone 4, Droid X and the Evo — will give you better wireless internet performance for a longer period of ownership. And these are all still compatible with B/G, so you can connect with most hotspots and home routers now, and will be set up for faster internet as it becomes more standard. (One note though: If you have a dual-band router at home, you’ll want to note that the iPhone 4 works on the lower 2.4 GHz frequency, not the 5.0 GHz band.) Over 802.11 B/G, the iPhone 4 still offers faster performance for internet surfing via Safari, compared to the 3GS, with zippy app downloads and vid/music streaming.
The iPhone 4 also now supports HSUPA, or high-speed uplink packet access. This boosts theoretical maximum upload speeds to 5.8 Mbits/second, which is much faster than every other iPhone model to date. Presumaly, it should make a difference when doing things like sending/sharing large image files and vids, as it can send them faster over the cellular network. (AT&T however has had some software problems with HSUPA lately, which actually slowed upload speeds down quite a bit, but the carrier announced it's working on a fix.)
Speaking of connection, that brings me to the final major topic area: Reception issues. By now, you’ve surely heard about the infamous signal glitches that result from hands interfering with the external antenna. Apple just had a whole press conference on the matter. The result? The company is offering free iPhone 4 cases to appease customers.
In my usage of the phone, I also experienced dropped calls occasionally — perhaps once a day in my own apartment. (I live in New England, in an okay pocket of coverage in a generally unspectacular reception area.) This is isn’t exorbitant, considering how often I’m on the phone, but it’s enough to be annoying. I’ve taken to holding my phone at the upper sides or putting it down and using an earbud. This seems to do the trick most of the time. And yes, I downloaded software 4.0.1, and still need to do this. That update was only intended to make the signal bars more accurate and easily detectable, not fix the signal issue.
When I do have decent reception, voice quality is clear, without noise or echo. The clarity was good even on calls placed over speakerphone. And on Bluetooth, it felt like the person was right there beside me.
Click here to go to Part 5 of our iPhone 4 review: Conclusion