Has anyone had success trying this out yet? Not sure how complicated it will be. Just found out that the project I'm documenting had anticipated but probably not designed for the v2009 credit for this. I'm just wondering if after-the-fact calculations will be easier/likely to be more lenient on this one in 2009 or v4. I suspect it always gets more stringent but thought I'd check. I was contemplating using the v4 form as an ACP in 2009. Thanks!