I understand this way of thinking - inside my home I rely solely on my Peltor Optime 3 defenders; because why use anything lower? It's not like your ears care about the difference between a fire alarm or a door slamming, and if you're "over-protecting" when it's the latter- but then it ignores the need for subtlety when out in public.Yea the X4A practically glow in the dark. I only have the X4A and X5A. There was a review on Amazon from someone who had the whole series and recommended those two as the only ones anyone should need out of the 4.
If I simply didn't care how I looked when I was out, sure I'd just wear the Optime 3s everywhere, but fun fact: I do care. I'm sure you can relate, residing in California, but I live in a part of London that is residence to (arguably) some of the most attractive women in the city, and I don't feel like being out in front of them looking like some sort of lunatic space-cadet.
Hence when I'm not wearing earplugs I want my ear defenders to look as much like (wireless) headphones as possible; so I go with the X1As in most cases. If your reactivity is more severe, then I can understand this not being enough for you, but I've been wearing Optime 1s and X1As in an area populated with super-cars and Harley Davidsons for years, and they have so far been adequate.