Replying to Guitar Hero World Tour vs Rock Band 2

alright i'm looking for opinions from some people who may own one or the other...i love rockband i like the concept of it i have only played it at friends house though i don't like the guitar and i love the guitar hero guitars...i'm looking to get one over christmas break....what do you guys think is better? plus i heard world tour has what i've done by linkin park and i love that song...which has more songs? which is more fun? and how is the downloadable content for the two of them...thanks guys!