I'm very happy for him, but it's sad that Machado didn't win it too, because he will surely become a top 100, by def. Gil. And Rui deserve top 100 by a long time. But Gil is a mentally stronger player, so hope he will use that to beat GGL... Not going to be easy, tought... it would be magic to have a Portuguese player in an ATP event, especially in front of his fans, in Estoril.
Rui seems to me to have a heavier ball and hit the ball better in general than Federico but he lacks a great serve, he gets stuck behind the baseline too much, and he got tired badly vs. Frederico. At the end, the fact Frederico spent a year playing ATP events is what made the difference in that match, his experience level and as you say, mental strength. But Rui is better than some of the guys in the top 100 right now, I'm sure he will get there sooner rather than later.