It would be helpful to know where you're flying from. That said, Polaris seat is better than the Vantage seat on most LX aircraft. With LX there may be an option to purchase an upgrade to F, which is a different level experience. And ZRH is my favorite connection point on the continent.

I suspect ITA will overall be a much better in-flight experience than UA (haven't flown long haul, but love them for short haul). And FCO is an underrated airport - certainly better than LHR, CDG, etc. The issues are (1) your MP earnings will suck if you're flying from the west coast on an ITA issued ticket, and (2) IRROPS would be a hassle, given one daily flight.