I think they suck big time. The Shield of Faith rule is a joke as is any rule that gives a 6+ for anything. A 1/6 chance at an invul sounds nice in the fluff, but never pans out and is essentially worthless. No army should have to pay points for a 6+ anything IMO. One-use Acts are idiotic. Acts that are restricted to individual units might be fine, but the ones they got are essentially worthless. And the idea of "getting into Rapid Fire range, but staying out of combat?" That works not at all. If you are in double-tap range you will be charged the next turn period, terrain or no terrain. The list goes on...
I have played Sisters since the end of 2nd Edition. They were my first ever 40K army and short of the interim PDF they released, this Ward codex is the worst ever. It is garbage. I would say they were throwing a bone to Sisters players had it been even remotely better, but it looks more like an insult to them. It's almost like the design team had a contest on how bad they could make a list and this is what they came up with. I imagine they had a good laugh at the pub afterwards...