I think when you say better it just shows that is question of people who don't understand basketball....What's better? It depends on the team, the offense, the situation, and what you need. If you run an iso offense and need a pure scorer to attack adn create, melo is one of the best in the league. If you have talent surrounding and need a 20-10 big who can impact both sides of the court but also do passing, but as a big you need a guard to get him the ball, players to spread the court, each team is different. Some teams would be better off with Gasol, some with melo, so there is no clear cut better and they both have their specialties
I think people are making this more complicated than it needs to be. It doesn't depend on what you need or what's your offensive scheme or anything. The answer is Gasol (and either one will do). Carmelo Anthony, for all his scoring and production, has never been able to make the whole team better. Gasol may be sidekick material, but he's a sidekick that can actually win a championship. Anthony just takes all your money and all your shots, and still doesn't win.