To be honest I don't watch the Portuguese league so the only thing I have to go on are his statistics and they don't give you any indication of how he plays. From what little I've seen of him in the European competitions he's a left footer who plays on the right and cuts inside. His league stats are very good but the Portuguese league is much weaker than the other top leagues in Europe. Going on his stats on Wikipedia in his senior career he's made a total of 178 appearances and scored 106 goals. It doesn't say how many assists he has but in the season just passed ESPN Soccernet say he assisted 4 times in the league, for some reason they don't have his Europa League stats listed on his page on ESPN.
He's still only 24, at the right price he'd be worth buying to see if he can improve in a more competitive and higher quality league, but I'd imagine as he's one of Porto's best players they'd ask for a ridiculous amount. I don't have any idea how long his current contract is or if there's a release clause but at the moment going on the clubs he's played for, and the stats he can only be considered potential and nothing greater.