Upside: The wide variety of XRT1-compatible products makes it possible to listen to Sirius's programming at home, in the car, and on the go. The S-Seek searching capability should make it easy to find the content you want, and the wireless remote should make it convenient to get there. In addition, the XRT1 (with the battery pack) is about $150 cheaper than XM's competing MyFi.
Downside: The compatible battery pack makes the XRT1 pretty bulky and allows only 3 hours of listening time--considerably less than the 5 hours the MyFi offers. The XRT1 also lacks some of the advanced features of the MyFi, such as the TiVo-like abilities to record satellite radio, display sport scores, and be used as an alarm clock. And although the XRT1 is cheaper than the MyFi, it requires one of the add-on packages to work and lacks the MyFi's extensive array of included accessories.
Outlook: Compared to the Delphi XM MyFi, the XRT1 just doesn't stack up. Even the lower price evaporates if you need to purchase separate accessories to listen in multiple environments; by contrast, the MyFi includes home and car kits, as well as an integrated rechargeable battery. If you like Sirius's programming and don't need the advanced functionality of the MyFi, the XRT1 could be a good way to get a bare-bones portable satellite radio at a reduced cost. But we're betting that Sirius will have a better portable option by the time Howard hits the airwaves in 2006. In the meantime, check out CNET's satellite radio guide to learn more about XM and Sirius.