I got my hands on two of the three new iPods—the Nano and the Classic (the iPod Touch is still a few weeks out)—and indeed, they make an impressive pair. Thin and light (especially the Nano) and packing snazzy new interfaces, they make for two of the most tempting iPods yet. But should you run out and upgrade?

Let's start with the "fat" Nano then—and yes, as an owner of a first-gen Nano, it's a big change. Short and squat (but feather-weight at just two ounces), the new Nano loses the sleek, slim appeal of its predecessor. That's not to say the Nano 3.0 isn't thin—at 0.26 inches thick, it's no fatty—but the boxy player simple isn't as much a pleasure to hold as the old, stick of gum-shaped Nano, which I always had a hard time putting down.

Of course, the new Nano's squat shape makes room for a two-inch screen that's packed with 204 pixels per inch—a quantum leap over the old Nano's puny 1.5-inch display, which looks like a pixilated postage stamp in comparison. On the other hand, the Classic's 2.5-inch screen looks pretty much identical to that of its predecessor, the 5.5-generation iPod—and indeed, save for its new anodized aluminum casing and slightly slimmer design (my 80GB test Classic is a good eighth-of-an-inch thinner, and half-an-ounce lighter, than my 80GB 5.5G iPod), it's essentially the iPod of old.

And then there's the new side-by-side interface (shared by both the Nano and the Classic), which is more of an evolution rather than revolution of the familiar iPod menu system. (If you want revolution, get the iPhone, or the upcoming Touch.) On the left, you get the standard iPod choices (Music, Videos, Photos, etc.), while on the right you get cover art that seems to float off the screen (it's the old "Ken Burns effect," of which Apple just can't get enough). Early reports had it that for movies and TV shows, you'd see brief video clips on the right side, but alas, that ain't the case; all you get is cover art for the film or show in question.

The new side-by-side interface leads to some interesting innovations: for instance, if you drill down to settings or extras, you'll see colorful icons for each feature on the right side (like a calendar page or a clock face). It's a nice touch, but overall I can't say that I'm blown away by the new UI—or at least, not enough to run out and replace my old Nano. Album art and icons on the right side of the screen are all well and good, but it won't change the way you browse menus in any fundamental way (then again, if you love the simplicity of the old clickwheel-powered iPod UI, that's a good thing).

The one big UI change, of course, is the addition of Cover Flow to the new iPods, and while it certainly does the job (it's a much easier way of browsing through albums than scrolling through a hopelessly long list), it's definitely slow and jittery—not at all the smooth experience I've come to expect on iTunes, or even the iPhone. Still, I liked that when you click a Cover Flow album, the cover art flips to reveal the album track list. Nice.

Besides the revamped UI, the experience of watching videos and listening to tunes on the new iPods is more or less the same, a few tweaks aside. One slick little change is that when you're listening to a song, the album art is tilted inward slightly, and a reflection is visible beneath—cool (and reminiscent of the Apple TV interface), but not earth-shattering. And if you were hoping to click a button to flip the "now playing" album art around for a track list (as you can in Cover Flow mode), prepare for disappointment. Still, a few iPhone UI improvement managed to sneak into the new iPods: for example, album art is now displayed on the left when you're browsing albums and podcasts.

Videos on the Nano and the Classic looked pretty good. Yes, the Nano's screen is tiny—I wouldn't want to watch "Lawrence of Arabia" on it—but for sitcoms or video podcasts, it works in a pinch. The Classic's screen looks a bit sharper and brighter than on my old 5.5G iPod—maybe a little too sharp, actually, adding distracting jaggies to the image. Also, I found that movies on both the Nano and Classic had an ever so slight jutter to them—not bad enough to be truly annoying, but enough for a fanatic like me to notice. That said, these are two of the brightest, most vivid screens you'll find on any portable device.

Extras on the new iPods are more or less the same as before: you get a world clock, a calendar, contact list, alarms, and a stopwatch. New this time around are three bundled games: iQuiz (a slick trivia game, complete with music), Klondike (a card game), and Vortex, a cool 3D version of Breakout.

Both the Nano and the Classic have the standard iPod connector, so both should work with most of your iPod accessories—that is, unless you have a device that's designed specifically for the old iPod, in which case you're probably out of luck (or in need of an adapter). Oh, and I almost forgot sound quality—impressive, if you ask me, with plenty of detail on the high end and big, boomy bass over my Shure SE110s. Maybe an oscilloscope would tell a different story, but my ears are perfectly happy.

So, the verdict? If you've never owned an iPod before or you're still using the 5GB iPod (yep, I've still got one too), this is a great time to jump in. With the new UI improvements and trimmed-down casings, these are two of the most highly-evolved MP3 players on the market. I'm also happy to see that Apple's pricing is, for once, in line with the competiton: $150 gets you a 4GB Nano with video, while $250 delivers an 80GB Classic (compared to $200 for a Zune with just 30GB of storage).

But should you upgrade if you have a newer iPod? Depends. If you're desperate for video on your Nano, then by all means, go for it. However, while the UI improvements on the new iPods are nice enough, there's nothing here that really demands an upgrade. Personally, I'm keeping my 1G Nano and 5.5G iPod, for now. And besides, if you really want new, you may want to wait for the touch-screen, Wi-Fi packing Touch, due to hit stores soon.