I somewhat equate NRE with the oldskool term infatuation
. It's that giddy, highschool, head over heels feeling that may or may not actualize as love down the line. The only test of whether NRE is based in reality, or just a mix of heady dopamine and fantasies is time, in my opinion. Over time, you get to know a whole person, and discover more and more if you are truly compatible.
I totally agree that NRE has been surpassed when you see all sides of someone, and you still care deeply for them, and can accept and love all of them. For me, this is somewhere between eight/nine months and a year and a half.
For me NRE feels unstable, and love feels more stable. NRE feels more like a sugar high, and love feels more like a nourishing meal.