Right now the SoBs are my primary army, the other armies I play are Tau and Daemon Hunters but they have been a bit neglected since I started playing sisters.
My first impression of the SoBs game wise, was that they were like watered down space marines. They had simular weapons but had a lower strength and toughness, needless to say I wasnt all that impressed. It wasnt untill I started playing against my buddy's SoBs and had my ass handed to me a couple dozen times that I, started singing a different tune. I was totally caught off guard by their furiousity, and I quickly learned that the sisters were no one to mess with. That Canoness was something to be feared alright, and those Acts of Faith were just obnoxious!!! After that, I had found my calling.
As a SoB player, I'd say my experience with the sisters have been pretty good. I've earned a good amount of wins, and I've had a fair amount of losses aswell. I have had only a few major loses, otherwise things were pretty close. The sisters are a pretty solid army and can perform well in many different situations. Acts Of Faith can and will save your life, and will allow your army to perform amazing/terrorfing feats. I think alot of players kinda scoff at the sisters at first glance, only to be caught totally off guard by their Acts of Faith.
Oh, and if you like flamers, then sisters are totally the way to go. Oh boy can they lay down some heat... I suggest bringing a pair of sun glasses and a bag of marshmellows
ID