This flick was just OK for me; the previews implied that a lot of content would be spent on the music of Woodstock, rather than the "back story. Some of the acting was pretty wooden and the characters were not very credible. C+ at best.
Great acting, well directed, good story line, a bit slow in the first third; this movie would have benefited from being 15 minutes shorter. But it is still one of the better movies playing this holiday season.