I went out and flew for an hour today. The NuShield does help with the glare, but it's not perfect. Is it worth the money? I'd say yes, if for no other reason than to have the screen protected. The iFly still needs an actual sun shade. I don't think much is going to help with sun washout.
For those of you interested in ordering the NuShield, until they get the iFly listed on their site just order the Amtek UMPC 7" dayshield. It has the same dimension screen as the iFly.