Hi! To report after the trip, my EZE-FCO flight was finally delayed two hours, which ate most of my three-hour connection.
I thus didnt have the chance to go out and try the Dolce Vita lounge, and just went to the schengen lounge for a few minutes - indeed, it was far from fantastic (and a long way from most of the schengen gates Alitalia uses !).
On a side note, I was surprised to see that Alitalia does three meal services on the 13-hour EZE-FCO flight, with the second service in the middle of the night... I'd far prefer two good meals instead of the three mediocre ones (and being awoken in the middle of the flight !)