You really need to carry a threat set and a mitigation set to deal with different group comps. If I am tanking a hard hitting boss, I will put on my mitigation gear which gives me a raid buffed 21k health and about 600 spellpower (buffed). If I am trying to stay ahead of pumper dps I go for something like 17.5k health buffed and near 1000 spellpower (buffed with flask of light). Oh, well and sometimes you need to carry a healing set when the fight only needs 1 tank…and a resist set for fire. I have like 3 bag slots available and I run 20 slot bags.