I've had it done and it was fine. Clearly there's a range of experiences possible, you may as well be optimistic.

I’m about to have it done in a few weeks. Hope yours goes well.

Just to calm your nerves. I had mine done today and, despite the intermittent choking and gag reflex, it was actually completely fine. Turns out I have Barrett’s esophagus, maybe caused from acid reflux and stress I've had since a kid. Slight increased cancer risk so I'll be getting this procedure more often from now I guess. Hope yours all goes well!