I'm no longer a hardcore P-38 driver, now just the occasional hop, but I will say that I definitely noticed a stall characteristic difference since the update.
Before, when I used to fly with the 475th in the MA, I only once (EVER) went into a tailslide-stall with it, and that was in a J. Every other time, it either flipped over onto its back or snapped the nose down. Very rarely it would flip over a wing and drop that way. Rarely spun.
Since the update, I tail-slid 3 times in ONE DAY, several times went into a reverse snap (rolled left in a right turn), and even stalled out on a short approach.
It also seems to mush a lot worse when pulling out of a dive or trying to snap the nose up, but that may just be me.