It is one of the easier raids, HOWEVER, there are many paths, and no functional map. The map only shows the outside parts, but the inside parts are where most of the raid happens and those have no maps. You could easily spend 2 hours in there exploring and/or getting lost. However however, the more optional paths you do, the easier the end fight becomes. (only the fire+ice part is required). It does have a mandatory stat check though. It's not high, but it does exist. In the heroic version, you need an Int of 20 and a Str of 20. The legendary version is much higher and varies by difficulty... but the heroic one is 20 for both Int an Str (does not have the be on the same character) is required.
edit: misremembered a thing, both stats are required unless I'm misremembering another thing. I'll probably go in and double check the paths at some point. Also, some areas are also behind locked doors.