We cannot call either Real Madrid or Atletico Madrid weak. Both teams have the ability to qualify for the quarter-finals. Most of the bettors consider Real Madrid as the favorite because Real Madrid is more experienced in the Champions League.
Both Real Madrid and Atletico Madrid are strong teams, it is strange if there is a person who claims one of them is a weak team. 
Sure, both of them have a chance to go to the next round since they have the same aggregate now. But if we consider the history of their matches, Real Madrid is surely more superior. Don't forget, Real Madrid is one of the teams who often win the game through "come back" scheme!
Madrid are still trying to dismantle Atletico's defense which is quite consistent with their bus parking and counter attacks which have been quite effective for them so far.
But as you say the match is still quite long for now and Madrid and Atletico still have the opportunity to qualify for the next phase especially for now their aggregate is still 2-2 so that in the remaining time remaining at this time there are still a lot of possibilities that occur only if Madrid wants to try to secure this match then apart from those who must be able to dismantle Atletico's defense they must also be able to stop Atletico's counter attack because for now the actual opportunity is more obtained by Atletico even though it is only from a quick counter attack.