Interesting that the Air gets substantially warmer than the base 17 when doing the same things. Neither one has a vapor chamber, since that's limited to the Pro models, so that's not the difference. It would be interesting to know how warm the Pro models get when doing the same things as on the base 17 and the Air, to see if the Pros' vapor chamber allows them to run even less warmly than the base 17. A vapor chamber might not have been possible for the Air since it would have increased the Air's thickness above Apple's target.