I have an '11 GSA that has never stalled, but does occasionally bog momentarily when I crack the throttle to match revs while downshifting. I chalked it up to the character of the engine, and found it likes "rolling" the throttle a bit more deliberately, instead of a rapid blip. I very rarely experience the issue now, and it's never seemed like a serious flaw. I've ridden enough old Harleys to know what REAL fueling/carburetion flaws feel like!
I apologize for the hijack, but I'm curious why rev-matching with the throttle on downshifts is no longer "necessary" or appropriate. I've been riding that way since I was 12 years old, to use engine braking without the abrupt engagement of a lower gear, and figuring it was easier on my clutch and trans. What am I missing?