Floor plans are useful, but I've found that even at FS properties the room layouts vary from room to room. This is especially true in renovated old-world properties like old palaces, etc...

My biggest pet peeve is getting a "1 Bedroom Suite" and literally having it be 2 regular connecting rooms, except one side has the bed pulled out and sofa put in. I realize this is the most practical way to create a suite, but it's just lame!