Originally Posted by
Pacer
Well first of all you need to specify for what class and what the purpose of the challenge mode gear is. If you just want to get gold you probably want your healer to have as much spirit, int and crit/haste/mastery (depending on best stat) as possible, while as a tank you want to gear as defensively as possible. If you are going for rank 1 times you want everyone to gear as offensively as possible.
That said items with your prefered stats who also has gem slots are BiS items, the higher the item level the more stats you will also get. Yes items do get scaled down but a HC TF item with same stats as an item of level 463 will have up to 40 more stat points, while not much it is something that does help.