Your going to experience two positive things by this switch. While the screen may be smaller, it's a heck of alot better. Is it as good as the One X screen, I'd have to see, but my guess is that it will be better. And second, you can take a picture in low light.
Good to switch ever once and a while. You get better perspective that way. Also, give it a more to the end of the return period to render judgement? It will take some adjustment and you have to give that some time or else you end up making a hasty decision.
What horrible advice to suggest he go beyond the return period if he doesn't like it. That's the whole reason for the return period. Are you willing to pay his early termination fee if he goes beyond it and still doesn't feel comfortable with it? I don't think so.