So? They were outplayed by most of the teams at the Euro, but with hard work and team spirit they pulled through. They also have the greatest goal scorer in their team and some technical players to support him with above average service. And a top manager to put it all together.
To be honest, Portugal aren't a great side, but they are a good team and I'm not sure teams can afford to treat the European Champions lightly.
I guess you could say they play "better" as a team than Argentina, due to having worse players on paper in many positions. Overall though, they are both very average sides at this stage, dont expect miracles from Ronaldo today, Uruguay CB pairing will most likely shut him and Quaresma(to some extent) down, they also have proper strikers to finish the game off.