We've used an account through a school for some time, however more recently we've been finding out that it's been problematic, particularly with some of the schools economic problems.
This year, the school itself put very little into funding our team, and money from our other sponsor was put into the school account (For various reasons unrelated to this discussion), however now because of the school districts financial issues, we have to put in a lengthy request and wait several weeks before we can use any of the teams own money, and requests can be denied (though we haven't had a problem with this... yet).
I'm beginning to like the idea of having a Non-Profit Organization team more and more.