I know you both well enough on these forums to know neither of you are traveling with (non-grown) children! I routinely check a car seat to Europe, often with a transfer, because I have to, and I'm really not worried about it. From 2012 when my daughter was born to today, the only airline to not deliver my luggage at the carousel has been AA on domestic travel. Don't get me started on that, it's usually my car seat, and always when originating at PHL.

With a nonstop flight from the US to MXP, I wouldn't think twice about checking a bag. It either gets loaded on the plane or it doesn't, with no opportunity to get lost in transit. If it doesn't get on the plane, it'll get on the next flight and they'll bring it to you. Pay for the trip with a card that provides decent luggage delay coverage, or buy more comprehensive trip insurance, and you'll be all set. Then, if your suitcase is a total loss, you can go on that shopping spree. Then again, I'm not attached to anything I own all that much. If they get lost, I'm buying new stuff anyway, which just defaults me back to the suggestion to not bring much.