For me both dramas start out poor and with a dark tone that is not what I expected from a romcom. But "Introverted Boss" gets better from the rewrite in episode 5, and it becomes spongy from episode 6 onwards! However it is not the story, nor the characters, what I like most about this drama! What I like most is the writer's sensitivity in capturing small moments.
On the other hand "Tomorrow With You" continues with much mystery, sometimes it is a little frustrating and the characters are imperfect. But it's a different and refreshing drama, far from tropes, and I like that! Also for me they are a very cute couple! Both dramas have very good kisses!
Both are good choices! I prefer TWY, but IB is lighter!