It's been a while, but there's a particular level range, (I want to say in the late teens to early 20s), where you're fighting a lot of CoT ghosts and, IIRC, Death Mages, that can just overwhelm you with tohit debuffs, and in that level range, you are sorely lacking the extra powers, slots, and/or IO set bonuses, to adequately combat them. Similarly, unless you specifically have slow resists, your recharge can also get floored, leaving you nigh incapable of defending yourself...