But the interface is smooth and intuitive. Double-tap on the home button to call up the multitasking bar, which appears at the bottom of the menu screen just up from the home button. The bar shows four icons across the bottom of the screen at a time, the most recently opened apps will have icons starting at the left; flick your finger left to right to scroll through the other icons (the one furthest stage right being the one opened the earliest). If you want to close an app out of memory, you press and hold the app's icon, and then click the red circle with a dash.
The Android approach is more wide-open, but harder to navigate. Android will keep other apps actually running in the background, and not just in a suspended state as iPhone does. For example, in Android a Web page might continue drawing, even after you have left the browser to do so something else.
To see your open apps, you can press and hold the home button. But wait-you can only view six open apps at a time! Unfortunately, the only way to see all of the apps running at any given time is to dig down into the Settings/Applications/Manage applications. Once there, you must then scroll down to Controls and press Force stop to close the app.
You can, however, download a third-party app, like Advanced TaskKiller for example, to make viewing and closing open apps easier. For some users, this might be a burden-why can't you view all of your open apps by simply pressing a button ala iOS4? On the other hand, some users enjoy having this sort of control and customization over their phone and the Android platform's openness certainly allows that.
Winner:Draw. It really comes down to personal preference.
The Specs: According to Apple, the iPhone 4 has an audio frequency response of 20Hz to 20,000Hz. It supports AAC, Protected AAC (DRM-protected content from iTunes), HE-AAC, MP3, Audible, Apple Lossless and WAV. In terms of video, the iPhone supports H.264 video up to 720p, MPEG-4 and Motion JPEG formats.
The Droid X supports MIDI, MP3, WAV, AAC, AAC+ and eAAC+ audio files. It supports HD playback via its HDMI and DLNA ports as well as H.263, H.264, MPEG-4 and WMA video formats.
Testing Methodology: I didn't have time to run PCWorld's audio tests to judge the Droid X and iPhone 4's audio quality so I did some very casual testing. I loaded the same MP3 on both phones ("Fazer" by Quicksand) and listened with my own V-Moda Remix Remote earbuds. I also played the song back through the external speakers on each. I also asked my PCWorld colleagues to give their feedback for the song on each phone.
Video was tougher to subjectively test. I couldn't fairly compare YouTube videos because the iPhone does not have the HQ feature in YouTube (on Droid X's YouTube app you get a feature called HQ that enables you to watch better-quality videos if they are available). Even so, I compared the same "Despicable Me" trailer on YouTube on both phones. I also had a hard time finding one H.264 file that would play back on both phones. I downloaded a couple of trailers via iTunes and rented a couple of HD movies to play on the iPhone 4. On the Droid X, I downloaded a few H.264 format movie trailers from h264info.com. For whatever reason, I couldn't get the Blockbuster application on the Droid X to work so I couldn't rent any feature-length movies.
The Winner: Droid X for Audio. Draw for Video. It was a close call, but my colleagues and I unanimously picked the Droid X over the iPhone 4 for better sound quality. Bass sounded deeper while vocals sounded crisper and richer over the Droid X. We noted a slight tinny quality during playback over iPhone 4, but everyone agreed that sound quality was still quite good.
Video was harder to judge since I couldn't play the exact same file on both phones. When HQ is available, video playback via YouTube on the Droid blows the iPhone out of the water. If you watch a lot of YouTube videos, this is something you might want to consider. Then again, it was incredibly easy to download movies onto the iPhone via iTunes directly on your phone. Using a third-party Web site like h264info.com is risky, not to mention time consuming. Playback on both phones was smooth with no stuttering, pausing or pixelation present. And while quality looked better on the iPhone (see our displays comparison), I really appreciated the larger screen for video on the Droid X. My eyes felt more comfortable watching videos on the larger screen where faces and objects are larger (though not higher resolution). On the iPhone's 3.5-inch display, I had to strain my eyes a bit.
The Specs: The iPhone 4 runs on the same A4 chip found in the iPad, but Apple has not disclosed its clock speed (though in the iPad, it's 1GHz). The Droid X has the first TI OMAP 3630 1 GHz processor.
Testing Methodology: To test the processor, I timed how quickly each phone downloaded a blank e-mail message with a 1MB .JPG attachment over Gmail. I did this test three times on each phone.
The Winner: Droid X-at least in this test. The Droid X had an average time of 7.3 seconds to download the attachment while the iPhone 4 took slightly longer at 10 seconds. Really, both phones are fast. This is just one example of an area where the Droid X is slightly faster.
Senior editors Tim Moynihan and Mark Sullivan contributed to this report.
This story, "iPhone 4 vs. Droid X: A Head-to-Head Comparison" was originally published by PCWorld .