DVD-burning junkies have been clamoring for the double-layer DVD ever since the first time they tried to pack an uncompressed, full-length movie onto a 4.7GB disc. Sony has heard your cries and will soon introduce two of the market's first double-layer DVD burners: the internal DRU-700A and the external DRX-700UL.

Upside: The DRU-700A and the DRX-700UL will let users write up to 8.5GB on special double-layer media--that's about 4 hours of DVD-quality video or 16 hours of VHS-quality video. The drives will also feature the current generation's read and write speeds for DVD+/-R and DVD-/+RW burning. Plus, for the first time, Sony will ship its drives with Nero--one of the first software packages to support double-layer recording, and one of our favorites.

Downside: The introduction of double-layer drives also ushers in a somber slide back to the bottom of the speed scale. The DRU-700A and the DRX-700UL will support double-layer writing on only special DVD+R DL media, and they do so at a drowsy 2.4X. The DVD+R DL discs, however, should be compatible with most set-top DVD players and DVD-ROM drives.

Outlook: We're psyched. Instead of the slow, incremental upward crawl of recording and writing speeds, the double-layer drive offers real innovation with the leap it takes in DVD capacity. Expected to start burning up retail shelf space this summer, Sony's DRU-700A will sell for $230, and the external DRX-700UL for $330. They'll undoubtedly have steep competition: BenQ, Pioneer, Lite-On, and Philips have also announced double-layer devices, all geared up to hit around the same time.