Have you ever looked at a can of Coke and a can of Pepsi and thought to yourself, "Really, what's the difference?" Some people look at these two products and figure they taste pretty much the same. But many, after some careful taste-testing, can point out the differences between Coke and Pepsi -- most think Pepsi is a little sweeter, while others say Coke has more bite and fizz. They may look and taste similar, but there are a few subtle qualities that set them apart.

The same could be said for satellite radio. You can glance at the list of stations available from the two satellite radio companies, Sirius and XM Radio, and not see much of a difference. Both have lots of channels devoted to classic rock by decade, today's hits, hip-hop, soul and other music genres, mixed in with a hodgepodge of news and talk shows. Does it really matter which one you choose?

The co­mpanies proposed to merge in February 2007, and after more than a year of lobbying, debating and numerous filings, the Federal Communications Commission (FCC) approved the merger on July 25, 2008. Like equal parts Pepsi and Coke, the companies have combined their business operations to form Sirius XM Radio, the only satellite radio service consumers in the United States can access.

Satellite Technology

There are still subtle differences between XM and Sirius, and despite talk of a universal radio that can access a la carte packages, for the moment you still have to decide between one or the other, and the type of service you choose makes a difference. Each company has their own phalanx of celebrities -- for example, if you're a Bob Dylan fan, you'd probably go with XM; if you want cooking tips from Martha Stewart during your drive, you're better off with Sirius. The sports coverage you enjoy could also affect which satellite service you prefer, as XM and Sirius ally themselves with completely different sports. The closer you look at each service, the more variety you might see.

In this article, we'll compare Sirius and XM technologies and services and find out what the experts have to say about the future of satellite radio.