I've only had some peripheral experiences with them, but they've been positive. Some folks who worked with ACORN on the east side of the state came and rallied/petitioned with us re childcare funding issues here in MI.
Also, I met some people at the SOA protest who were employed directly by ACORN in the DC area somewhere..they were focused on affordable housing.
The ones I pity are the ones who never stick out their neck for something they believe, never know the taste of moral struggle, and never have the thrill of victory. - Jonathan Kozol