The difficulty of raids varies wildly depending on the server you are on. My old server had pugs clearing normal mode easily and downing some of the easier heroic bosses...hell most of FL/DS was pugged on heroic. On the server I moved to in order to play with friends, you'd be lucky if a pug got past horridon on normal mode. The discrepancy is pretty depressing. Basically it all depends on the health of your server's raiding scene.