To address the pain, I have a NExT in my RH at P0, standard location, right? Basically the needle feels like being stung by a wasp (on purpose). Once it’s in, only minor minor pain. Will throb for an hour or two afterwords, which is why I recommend taking a tylenol / advil prior to installation. That way it’s already in effect.
Short story, feels like a wasp sting, take asprin first.