Are NanoBags actually a good long-term reusable bag option?

I’ve gone through a ton of reusable bags over the years — most either tear, stretch out, or just get nasty after a few uses. I recently came across NanoBag, and it caught my eye because it’s supposed to be super light, durable, and packs down tiny.

It costs more than your average reusable bag from the store, so before I grab one, I figured I’d ask here: is it actually worth it? Anyone been using one for a while?