You can't rip the song's like you could from Rock Band 1 to Rock Band 2. I was under the impression when I paid for the ability to rip songs on Rock Band1 that I would be able to do it on all future Rock Band games, maybe because it said that on the game. But with these track packs you cannot unless you buy the disk. They are wort it if there are several songs you really love and they have easy achievements but overall play for a week and send it back.
Looking for some new tracks for your dusty Rock Band kit? This is a good buy if you don't have XBox Live connected. Otherwise you can buy the ones you want ,and avoid the others. It's cheaper than buying all of these one at a time.