(I've technically been eligible since mid-2015. But since I didn't book a gig where it mattered for another three years, I wasn't exactly holding my breath about it.)
So that's cool. I'm not a sign-waving "go union" kinda guy. To be honest, I'm not all that impressed with sag right now, given the Hoffman case.
But that said, it's pretty much universally acknowledged as a professional milestone in my industry. One I worked my ass off to earn. So I'll treat it as such.