I believe that De Rossi's Roma would stand more chance against Milan. They failed with Mourinho against them. They lost twice in their domestic league. However while there is good progress in Roma football I'm more expectant from them. Because above all else they have started to play an effective attacking-oriented game. 
This was what Roma needed. Mourinho was just placing obstacles ahead of Roma because of his boring defensive strategies. Roma aren't a good defense team. We must have all understood it so far. They need to play more attacking to balance themselves.
Milan are still a tough opponent but Roma have more chance to advance after some important changes made by De Rossi.
There has been a significant increase in performance since Roma were coached by De Rossi, but we also shouldn't underestimate AC Milan, the AC Milan team is currently in its best performance after they had a little difficulty at the start of the season and because of this, it is possible that the two teams are quite balanced. to qualify for the semifinals.This was what Roma needed. Mourinho was just placing obstacles ahead of Roma because of his boring defensive strategies. Roma aren't a good defense team. We must have all understood it so far. They need to play more attacking to balance themselves.
Milan are still a tough opponent but Roma have more chance to advance after some important changes made by De Rossi.
I see the overall strength of the two teams, even with the mentality that both teams have, De Rossi is a new coach who doesn't have much experience, especially on the European stage, this will be a fierce match for both teams with high match tennis, so I really don't think there is any too much of a favorite team.
Regarding choices in betting, perhaps each of us is different and has our own favorites from different points of view.
There's nothing wrong if you really believe in Roma being able to beat AC Milan.