When it comes to the Creative Zen Vision:M's 14-hour claim, CNET got about 16 hours of playback time with MP3s from a full charge, which was a nice surprise. However, when they tried playing WMA 10 DRM crippled subscription tracks on it, they only got just over 12 hours - a loss of almost 4 hours (~25%) of playback time due to the battery-hungry DRM.

We found similar discrepancies with other PlaysForSure players. The Archos Gmini 402 Camcorder maxed out at 11 hours, but with DRM tracks, it played for less than 9 hours. The iRiver U10, with an astounding life of about 32 hours, came in at about 27 hours playing subscription tracks. Even the iPod, playing back only FairPlay AAC tracks, underperformed MP3s by about 8 percent. What I'm saying is that while battery life may not be a critical issue today, as it was when one of the original hard drive players--the Creative Nomad Jukebox--lasted a pathetic 4 hours running on four AA nickel-metal-hydride rechargeables (and much worse on alkalines), the industry needs to include battery specs for DRM audio tracks or the tracks we're buying or subscribing. Yet, here's another reason why we should still be ripping our music in MP3: better battery life, the most obvious reason being universal device compatibility.

As AAC and WMA10 have higher compression of the music, it's likely they need more decoding power compared to MP3, which is why the battery time is reduced. I'm sure the DRM will reduce battery life a little, but not by nearly as much as is claimed here!