i have a friend who used to live in PT for years and years and saw restaurants come and go. Mediocre was usually the highest level they ever reached and his opinion of Caffe Italo was about the same.
Now, I have no specifics on their mediocrity -- and in full disclosure I never ate there -- but the reason I never ate there was that after one meal and one very lousy pizza (so maybe I do have specifics!) he refused to ever go back.
And he's not nearly as picky as I am.
There are better choices for pre opera dining -- Rivers, the Golden Budha, even Blackie's for a good burger. Emil's is sort of a greek diner with white tablecloths and okay food -- not incredible but I've managed to have a decent risotto there once or twice.
Good luck!
Shannon