hahah yah, to me it's a distinct cola syrup flavor in both the sweet tart and the harry Chanok. I don't know of any better way to describe it.
In regards to the Maha Chanok, if eaten very ripe, the cola syrup / south east asian spice is not detectable. In this state, the mango is bland and boring and hence why I never liked it before. But when eaten in the state that some might consider slightly underripe, it's very noticeable.
Another way to sense the "cola syrup" flavor is to smell the sap that exudes from the cut site just after harvesting the mango.
I've also noted that the "middle class" end of the mango eating population tend to eat mangoes using an elaborate technique whereby the mango flesh is sliced into cubes and eaten as if it were hors d'oeuvres. In that format, I believe the flavor near the rind could be lost, since it's difficult to scrape the flesh from the skin with one's teeth. (More importantly, it's difficult to wolf the mango down when separated into 30 little pieces. :-)
I generally cut the mango into 3 pieces, with the seed in the middle. Then, I scrape out the flesh from the 2 end pieces with my teeth, which, in addition to ensuring that no delectable morsel of mango meat is lost, probably enhances the rind flavor :-).