I bought the online version, I found it to be a very useful resource throughout the application process. One example of a useful bit of info out of it is the ratios of interviews/acceptances. For example, you can see that at some schools you've got about a 50% chance once you've been invited for an interview, while at others its more like 20%. Also, being able to see how many out of state applicants a school will take is useful. There is also info about tuition, average student age, average indebtedness, average MCAT and GPA, etc. etc. etc.
So, in short, there's a lot more info than just the rankings, and with the online version you can compare several schools at once for any of the intersting bits of information.