I agree with this, and don't think I'd have a problem stepping into a tested, functioning transporter.
Still, when the scenario is changed only slightly, it gives me pause.
Suppose you're transported five feet from where you are right now, and the "original" is not vaporized. You now exist as two virtually identical individuals. You can even have a brief conversation with yourself to verify that your memories are exactly the same.
Would you be happy now to step into the vaporization chamber, knowing that your emergent brain activity is cycling along just fine in the other body?
Well, to be honest, I wouldn't step into it anyway. I'm hard-wired to resist death.
But, having participated in a lot of these debates over the years, what I see repeatedly is that people always go into these scenarios with the chamber malfunctioning, or the idea of meeting your twin.
And actually these things have nothing to do with the original thought experiment. They're just emotive concerns, biological pre-programming.
The thought experiment is usually used to demonstrate that many people who profess to be materialists won't actually choose to believe it when their own body and sense of self is at stake. Me neither.
Most well-functioning human beings will choose an inconsistent belief over hard reality when their sense of self is at stake. Because, at the end of the day, no one really cares that much about philosophy or science.
Nick