What is the difference between first and second class train travel in Italy? Is it worth the additional 10E per person for the first class?

Second class is fine. Milan to Venice is about three hours - no big deal.

The seats in 1st class are slightly larger and there may be less people. I find the seats in 2nd perfectly comfortable--more comfortable that airline coach seats.

First Class makes travel easier if you have more luggage - since there are fewer seats in the sane space. If you have only a small carry-on Second Class is fine.

We always do First if we're travleing with luggage (versus a day trip).

The first class seats are in front of the dining car. The only time I sat is second class we had people constantly in the aisle going back and forthe to the dining car. It was hard to read or sleep. 1st class is quieter and more comfortable. We travel to Italy once or twice a year to see family. Before our family visit we travel to other areas mostly by train and sometimes by car. We only go 1st class now.

Thank you all! We're still deciding since we do have some luggage but only small suitcases. Perhaps it will come down to how tired we are after our flight. Appreciate your replies.

Windy we went from milan to venice by train in second class just one month ago.. it wasn't crowded and although i haven't travelled first class to compare, 10euro/person more seems likes it's not worth it for me. The train and the seats in second class are really comfortable.
(have in mind that booking your tickets through trenitalia website with the amica fare is even cheaper)

And you can spend the ten Euro that you save on wine in the refreshment car .............

Been there. Done than.
No big deal... you can do it.