As digital MP3 players morph from audio devices to multimedia players, one thing remains constant: the brand name on most of them. Apple’s iPods still account for more than three out of four units sold.

Many other companies make players, however, and others are poised to join them. That includes Microsoft, whose Zune players are expected later this year. They’ll have wireless capabilities allowing users to share music, photos, and playlists with other devices. Meanwhile, new music phones are blurring the line between cell phones and MP3 players.

Dominant as it is, the iPod has its flaws. That point is reinforced by the findings of an exclusive Consumer Reports National Research Center survey, conducted in July 2006, of 3,000 Consumer Reports subscribers who own iPods and other players. Here’s our updated advice on choosing an MP3 player, based on this survey plus our testing and reporting:

Our survey quantifies some distinctions that have helped make iPods iconic. They’re easy to use; more than 50 percent of owners reported that iPods’ controls and music management (on the player and when transferring music from computer to player) were excellent. No more than 35 percent deemed those to be excellent on all other brands combined. (Because of Apple’s market dominance, we’ve aggregated data on all other brands. Specific brands may vary, but sample sizes are too small for us to comprehensively compare iPods with any one brand.)

Also, 65 percent of iPod owners described the players, including the display, as excellent in appearance, nearly twice the proportion for the non-iPod group.

CR’s take. iPods remain a leading choice in digital players for ease of use and appearance. The players work almost seamlessly with their iTunes music-management software, and the iTunes Store is the biggest online content retailer, with many exclusive songs and videos.

Overall, iPods have been as reliable as the other brands combined. But the survey confirmed that battery life per charge has been a weak spot for iPods, which (like many other players) have rechargeable lithium-ion batteries.

About 20 percent of iPod owners characterized their player’s battery life as excellent, compared with 30 percent for the other brands. That echoes our tests, in which iPods often score somewhat below their best competitors in battery life.

Our tests can’t cover the effects of aging on batteries. But in our survey, about 29 percent of those who owned hard-drive iPods that were one or more years old reported that battery life was much shorter now than when their player was new. Just 15 percent of the non-iPod group reported having that problem.

Apple has acknowledged premature battery failure in some iPods bought before June 2004. But our data suggest problems even with newer units. When we limited our analysis to iPods that were at least one but no more than two years old, the findings were similar: 26 percent of owners still reported shorter battery life.

The survey also records owners’ responses to some other potential drawbacks. iPods lack the FM radios and voice recorders on many other brands of players, and iPod owners were half as likely as owners of all other brands to describe their player’s array of features as excellent. About 14 percent of iPod owners complained about having to turn on their computers to charge their players, via the USB port. That’s more than twice the incidence for other brands combined, some of which, unlike iPods, come with chargers.

While Apple has long been the best-scoring brand in our computer ­tech-support surveys, scores for iPod support and for all other brands combined differed little, with about 25 percent of all owners describing support as excellent.

CR’s take. Though our data can’t predict performance for current iPods, our findings raise continuing questions about how long iPod batteries might last compared with those of other brands. And iPods are at best undistinguished in tech support and features.

Apple and most other brands offer players with flash memory and players with tiny, built-in hard drives. While size varies by model, flash players such as the iPod Nano are about the size of a credit card. They typically have 4 to 8 gigabytes of storage, enough for about 1,000 to 2,000 songs. So-called microdrive models are a little larger, and they hold up to 8GB. Hard-disk models have 10GB to 80GB of capacity that can hold about 2,500 to 20,000 songs, respectively. However, that huge library of songs can be complicated to manage on the player. Also, some multimedia players are comparatively large; typically about the size of a deck of cards.

CR’s take. Consider a flash-memory model if a lower price, smaller size, lighter weight, and long playback time are more important to you than a vast selection of tunes. Opt for the largest-capacity flash player you can afford. Capacity usually doesn’t affect size and weight, and you may pay only an extra $25 or so per GB of storage. If large capacity is most important, a hard-disk player may make more sense. Here, a more capacious model in a line may well be heavier and bulkier.

As with almost all other gear, service plans are a poor investment. For example, the Apple Care Protection Plan for iPods costs $59 for two years. But for respondents without a plan, the median cost of repairs, support, and battery replacement for a two- to three-year-old iPod was $65, and only 9 percent of players ever required any of these services. (A few owners did have to make very expensive iPod repairs, up to $200 or so. Also, plan buyers were more likely to use tech support, since iPods come with only 90 days of free support, less than most other brands.)

CR’s take. Unless you’re especially risk-averse (or technologically challenged and thus in need of frequent tech support), resist an extended warranty for your iPod or other digital player.