What are some thoughts on going warrant officer? What is the school like? How difficult is it to get in from a national guard stand point?

I've had people- friends, peers, superiors, and even some people on here- ask me if I've ever considered becoming a Warrant Officer, or suggest I put my packet in. And lately I've been giving it some thought on whether I should submit my packet or not. I love being an NCO and working with and taking care of troops, I also had a goal to retire as a CSM. But like everything else in life things change. So my question is is Warrant Officer the way to go? What are pros and cons, what are the benefits both short and long term, etc?