I'm obviously no expert as I rarely eat the stuff, but when I have had curry I've always found the heat to be a challenge. I know there are milder curries, but in the main the popular ones are too hot for me. I'm sure you know what I mean about the effect on your body the following day, how can a food that does that to you be good?
I've eaten chinese food on a regular basis for most of my adult life. What is this changeover you've mentioned. I genuinely don't know and have never suffered any reaction to chinese food at all