At 2.75 by 2.0 by 0.5 inches, the SanDisk Sansa e100 may not be the tiniest flash-based player (even some 5GB players are smaller), but it's very lightweight at 1.6 ounces with its single AAA battery. Despite the e100's durability, its feathery weight lends to its cheap plastic feel--glance at the buttons, and you'd think this was a promotional item.
Overall, the interface is intuitive, with its large, tactile main controller buttons, though they are not touch sensitive, despite appearances. The hold switch is on the left spine, while the right spine features the menu/power button, a handy expansion slot compatible with SD cards up to 2GB in capacity (conveniently available from SanDisk for about $180 on the street), and a dodgy scrollwheel. The original SanDisk MP3 player was more compact and pack-of-gum-like but lacked the expansion slot. The 512MB e130 ($140 list) comes in a sharp-looking blue, white, and silver body, while the 1GB e140 ($190 list) is silver and white.
The Sansa e100 plays MP3, protected WMA, and, handily, Audible files. The USB 2.0 device also has a stopwatch and an FM tuner with 20 autoscannable presets; however, it doesn't have a voice recorder, as the first SanDisk player did. While it lacks the line-in and FM-recording capabilities of the smaller but similarly priced Creative MuVo Micro, it has the most useful features (FM tuner, large LCD, and expansion slot) down pat. The interface, which sorts music by Play All, Artist, Album, Songs, New Music, Spoken Word, and other groupings, is simple to navigate, though the indigo-backlit LCD isn't the most legible we've used. Also, though the player breaks music into browsable groups, you can't listen to an album in order unless you append track names with numbers, and there is no playlist support.
One shortcoming of the design is the scrollwheel, which is located on the upper-right corner. It feels cheap and isn't smooth like the Rio Carbon's--not good, since it also acts as the volume control; in fact, adjusting the e100's volume is a true pain. Plus, this wheel isn't clickable; instead, you tediously hit the main Enter button to select. There is also an occasional processor lag of a second or two during navigation or song selection.
Sound quality is not impressive at all, despite the five EQs and the SRS Wow effects. Our test MP3s (which include Ikara Colt's "Don't They Know" and Bjork's "Headphones") sounded a bit dull, with noticeable background hiss. Also, the player couldn't adequately power a larger set of headphones. The FM-tuner scanning works well, and reception is above average. You get comfortable in-ear phones and an armband in the package, along with a USB cable and a AAA battery. The battery life is decent at 17.6 hours per AAA cell, compared to the company's rating of 17 hours. Transfer times over USB 2.0 were below average at 1.8MB per second. However, if you're on a tight budget, the $140 and $100 street prices of the 1GB and 512MB versions, respectively, might be enough incentive for you to overlook the performance issues. If you're a discerning listener, however, check out the Apple iPod Shuffle instead.