The HR21 is DirecTV's primary HD DVR. It features a 320GB hard drive and dual DirecTV tuners, which allows you to record two shows simultaneously or watch one show while you record another. The box supports MPEG-2 and higher-quality MPEG-4 signals. It does not contain internal ATSC tuners to pull in over-the-air HD content; if you live in area where DirecTV does not yet offer local channels in high-def, you should request the HR20 instead, as it does offer the internal ATSC tuners.

The back panel contains one HDMI, one component video, and one S-video output, plus dual composite video outputs - which allows you to send an SD signal to a second room (you can only watch the same content being displayed in the main room). On the audio side, you can output PCM or Dolby Digital 5.1 signals via the HDMI, optical digital, or coaxial digital audio outputs; two stereo analog audio outputs are also included. The box sports two Ethernet ports: One port allows you to add the box to your home network to order video-on-demand titles and utilize limited media-streaming functions (if you have an Intel Viiv PC); the other port serves as a pass-through to add attach other networkable devices. The HR21 also has two USB ports that are currently inactive, as well as a phone jack for pay-per-view and Caller ID display and an eSATA drive to add a larger external hard drive.

The HR21 supports 480i, 480p, 720p, 1080i, and 1080p resolutions; DirecTV recently announced plans to offer some video-on-demand content at a 1080p resolution and has upgraded the HR21's firmware to support 1080p output. The setup menu also includes a native option to output every channel at its native resolution, which allows you to bypass the box's internal (and mediocre) scaler. The setup menu includes some other nice features, such as the ability to designate a color for 4:3 sidebars (dark gray, black, or gray), which is especially beneficial for plasma owners who are concerned about image retention. You can also designate an aspect ratio for 4:3 content (original format, stretch, crop, or pillar box); the remote's format button allows you to scroll easily through the choices.

As for its DVR functionality, DirecTV's interface is solid and generally easy to navigate. Most of the desired recording options are here, such as the ability to set first-run-only recordings and the option to start recordings early or add time at the end. The recordings list provides an indicator that shows you how much hard-drive space is remaining, and the HR21 has a nice, long 90-minute buffer, plus a 14-day program guide. You can schedule programs remotely via the DirecTV website, and the box does not have to be connected to your network to do so. The number of HD movies offered via DirecTV's video-on-demand service is solid and growing daily.

The supplied remote control lacks backlighting, but the buttons are arranged in an intuitive manner. It can control the HR21 via either IR or RF, and you can program the remote to control your TV and two additional components. The box itself has a nice step-up look, with a gloss-black finish and a clean button layout. The front panel features a navigation wheel with a glowing blue ring, plus buttons for power, guide, menu, record, info, active, and resolution. Four LEDs indicate the resolution of the current channel. The Active button launches DirecTV Active, which provides access to local weather, lottery, horoscope, and customer service information.

Highs Points
- The HR21 has dual tuners and a respectably large hard drive, with the option to add an even larger external drive via the eSATA port.
- The box supports MPEG-4, and DirecTV's image quality, especially with HD signals, is very good.
- The HR21 will display TV channels at their native resolution (480i, 720p, or 1080i), so you can bypass the box's internal processing.
- DirecTV offers a great HD package.
- Some VOD content is available at a 1080p resolution.

Low Points
- While the user interface is solid, it's not quite as intuitive as the TiVo interface, nor does DirecTV offer as many enhanced services as TiVo.
- The internal scaler does only an average job upconverting 480i signals.
- Even though you must purchase the $300 HR21 (you can find it for less than $300 at many retailers, and DirecTV sometimes offers rebates), DirecTV still charges monthly equipment lease fees, in addition to DVR service charges.

Conclusion
The HR21 is a worthy HD DVR that offers excellent picture quality, reliable performance, and a nice range of setup options. DirecTV HD subscribers who wish to add DVR functionality should be generally pleased with the experience. However, it's worth noting that DirecTV and TiVo have rekindled their partnership and plan to release a new DirecTV/TiVo HD DVR in the second half of 2009. If you've waited this long to invest in an HD DVR, you might want to hold out a bit longer and see what the TiVo model brings to the table.