It's only been 4 episodes but Suzy hasn't had enough time to deal with the issues of her acting skills. The amount of emotions Suzy has to express through Noh Eul is deep and wide. However, her speech and awkward facial expressions is still out there on the table. She is yet to relate with Noh Eul's complicated emotions as well. Suzy started acting in 2011 with "Dream High" and she's led several other dramas but the controversy about her performance is still there.
Sometimes, there are reviews that Suzy did well in some parts of the drama. However, that's not enough for a leading actress who has taken on a 20-episode drama. A drama is not a practice for a single actor. The fact that "Uncontrollably Fond" is a pre-produced drama is also another concern.
It's a good thing that Suzy's performance is getting better by every episode. The chemistry she has with Kim Woo-bin is also the reason for the double-digit percentage.
One thing to go over is that the standard of evaluating an idol-actor doesn't reflect the fact that she's an idol. Regardless of the results of "Uncontrollably Fond", Suzy is already a good enough star to be recruited by other dramas. Hopefully, the drama will end with Suzy getting a standing ovation.