Actual use
In terms of day to day use, there's actually quite a bit of difference between the iPod and Zune—more than I was expecting. The main difference here is the user interface, which for something as simple as a personal media player, should be easy to get right. Simplicity oozes from the iPod's stark white menus, but navigating through them with the touch-sensitive click wheel is more than just a little cumbersome. First, the wheel itself doesn't click, so you actually have to take your thumb or finger off it to press the center button. That wouldn't be a huge problem in itself, but when combined with the wheel's high touch-sensitivity, merely moving your finger off it can change your selection. This takes some getting used to, and even after several months of use, it's still too cumbersome for my tastes.

By comparison, the Zune's standard array of navigation buttons looks a little bland. But the buttons work better. They really do. There's no learning curve to worry about, no sensitivity to adjust to, and little chance that you'll accidentally hit one of the buttons and inadvertently change your selection. Holding down the navigation buttons for a few seconds invokes a fast scrolling mode similar to that of the iPod, but you don't have to keep spinning your thumb or finger around to keep it going.

Touch-sensitive wheels are fancier than buttons, but not necessarily better

Scrolling is much smoother on the Zune, as well. In fact, the whole interface feels much lighter and more responsive than that of the iPod, despite the fact that Microsoft makes use of several fancy visual effects to smooth menu transitions. You don't get visual effects with the iPod, and that's probably a good thing, because it feels like Apple has pushed the iPod's hardware to its limits with the current UI. The interface just doesn't feel as, well, agile as the Zune's. And it gets worse when you're playing music in the background. That doesn't seem to slow the Zune down at all, but the iPod's interface gets noticeably choppy, especially when fast scrolling.

So despite its clean looks and fancy touch-sensitive wheel, the iPod's interface feels like a slightly uncoordinated fat kid trying to outmaneuver a considerably more energetic and athletic Zune. But then I've been using MP3 players for years, and maybe the click wheel was too much of a change for me, so I sat down with an impartial subject: my mom. Like most moms, mine's never owned an MP3 player, owes no allegiance to either Apple or Microsoft, and is just savvy enough to get her email, web surfing, and word processing done.

Watching my mother play with the iPod confirmed my reservations about the touch-sensitive wheel. She wasn't comfortable spinning it around fast enough to accelerate scrolling, and would often scroll right past what she was looking for. Additionally, she found that menu selections changed when she took her thumb or finger off the wheel to hit the center button, calling this behavior "very annoying." She didn't seem to care that the interface slowed down when music was playing in the background, though.

The Zune's simple button-based interface fared better with mom, who immediately figured out fast scrolling and seemed to have no problems with navigation. She even commented that the Zune's interface was "prettier" than the iPod's stark white menus, but that the device itself was a little dull, and "more plastic, you know." The overall feel of the iPod did appeal to her, though; she called the design sleek and "almost sensual," and that's where our impromptu test session ended. Sensual is not a word I need to be hearing in conversation with my mother.

Playback explored
Once you actually get some music queued up, the iPod and Zune offer nearly identical playback quality, provided you use the same set of headphones with both. I listened to scores of 320kbps MP3s back to back on each device, and would be hard pressed to rank one over the other. If anything, the Zune's bass response sounds ever so slightly sharper to my ears, but that's about it. Of course, if you swap in the stock headphones that come with each device, playback definitely favors the Zune.

The Zune's screen is much bigger, but not really much better

Moving to video, there's even less difference in playback quality. Video playback is smooth, screen brightness and color reproduction are comparable, and even the resolutions are the same. The big difference here is screen size and orientation. Watching video on the Zune is done at 90 degrees, so you actually have to rotate the device. It's worth it, though, because the difference in screen size is definitely apparent. There's simply more to watch on the Zune.

With both screens offering the same number of pixels, I expected the Zune's larger display area to highlight flaws inherent to lower resolution compressed video, such as jagged edges and overall blockiness. That wasn't really an issue, though. Sure the jaggies are bigger on the Zune, but they're no less annoying on the iPod, if your eyes tend to notice that sort of thing.

Of course, if you are picky about quality, you'll likely be dissatisfied with video playback on both devices. It's not so much that the resolution is inadequate (which it is) but that even the Zune's 3" screen is woefully tiny. Cartoons were about the only things I could stand to watch on either device, since so much detail is necessarily lost with other content. So the Zune may be technically superior here, but in the same way that the GeForce 8400 GS is superior to the 8300 GS—you wouldn't want to play games on either. Personally, I'd sooner listen to music than watch video on either the iPod or the Zune.