Many classes and specs like prot pally will be able to do at lower ilvl and proper skill. But if not in the upper ilvl ranges expecting to do it furthermore with ease, will be is a streach. At lower ilvl you will be gambling on powers and worse on the right bosses to win. Eg in my example of blueprint getting his mount if he got a bad boss do you really think he could live 6 and a half min when the boss is gaining his stacking buff the whole time. Even the upper layers are a risk at low ilvl if you dont want to be out a ton of time.