I have a friend that installed those. He has had them for almost two years. They have faded very badly. I guess you could do the Krylon fusion paint fix like the stock flares.
They actually do not offer any more flex than stock due to retaining the lip that the stock flare mounts to.
Last I spoke with him, he said he was looking for something else and will probably get rid of them.
They do look good though. Nice Jeep BTW.