I have No experience with couch surfing personally, but from what I've read, the guests tend to be pretty all over the board. You might get someone great who's traveling from Europe and making their way around the US. You might get some unshowered hippy who's just traveling just because he doesn't like to work to maintain an income and place to stay, and who you can't leave alone for two seconds because he'll probably smoke a bowl in your living room and not understand why that's not OK. It seems to be all over the board from what I've read. I've also read that there have been problems with hosts trying to get girls drunk and pressure them into sex. It seems like it's probably something that started out as a good idea, but due to complete lack of monitoring, became a potential **** show.