The thing about Gallinari is that I don't believe his efficiency has gone up, it's his usage rate.
http://www.basketball-reference.com/players/g/gallida01.htmlIf you compare his shooting percentages this year vs his breakout season at age 21, they are actually slightly lower for fg%, 2p%, 3p%, and efg%
So it's not his skill level that has increased rather, he's been given an increased role in the offense and he hasn't hesitated to take the shot that his team needs.
I believe Gallinari is a good player, but he's not the "star" player that we've been searching for. I also agree that Isaiah Thomas is more valuable because he provides scoring at a position, PG, that traditionally doesn't provide a lot of scoring except from a select few players, the Russell Westbrooks, the Chris Pauls, etc.
PS Hell no, I wouldn't trade I. Thomas. Finding his combination of skills and scoring ability in a PG is just too rare.