TBH the Americans seem to be suffering more of what appears to be software related bugs causing check engine errors and such like on their 2.0 Ti (280HP) and less so on some Qf's based on what's being posted on giuliaforums.com
From what we can see here in the UK, so far mechanically all versions of the Giulia are performing as expected or better. No real issues being reported.
Some niggles/oversight related to body, interior and RHD conversion.
A few early ECU sensor calibration issues mostly addressed by 611x with the exception of one or two unfortunate owners who had repeated errors that could be resolved by re-flashing software. These could be actual defects or issues with the sensors or wiring and hence not fixed by software updates, but AR inexplicably were incapable of attempting to diagnose if these were hardware related perhaps due to lack of dealer expertise or AR Technical guidance... we will never know!
The stuttering on the Multiair would be enough to erode my faith in the car as a check engine light represents something serious to me. I had the Eml twice on my previous Giulietta MA. The first time because the MA unit misfired at 15000 miles when I followed the advised service interval. Got the car low loaded to dealer who did oil change service and all was No new MA unit. Stressful and time wasting.
Next time was four years later due to gear position sensor. I went straight to dealer on way home. Engine warning light etc on a new car seriously makes you lose trust in it as you drive around until it can be diagnosed.
I have only had the CEL once in Month 1 that was covered as part of the TSB software update to do with Wastegate solenoid range error. The TSB also covered a few other CEL's. All fixed under 6118 and its predecessors as far as I can see. Mine has done 4800 miles, other 2.0 MA engines here have done nearly 10k without any issues. The slight hesitation/stuttering between low gears at cold start reported in another recent thread is slightly disconcerting, but has only happened once or twice with NO associated CEL. This feels more like a gearbox mapping issue but I can't be certain as it hasn't happened since. The car has been driving fine. I know what you are saying though, on a new car you want everything to be perfect and so far on the Giulia which is the only new car I have ever bought, the major positives have so far outweighed the handful of negatives. But it does erode your faith if repeated CELs occur as it did for Brooking or at least it blunts your initial enthusiasm. More than anything it just reminds us why we all drive Alfas!