I do not know Sonata is better or not, but they are not in the same category, so I am not sure why is there even a comparison.
I bought RS out of choice, more so cause I have a thing for Turbo engines, especially since we bought the first Civic Turbo here back in 2016.
The new RS is a great car to drive!
But I am not sure why anyone can be impressed with RS built quality!
I have a long list of built quality issues in my RS.
And they are something I will have to live with, cause I have lost count of my trips to Honda to solve them, and for most of them, Honda simply says that we are Sorry but we cannot fix them!
The best part is that I knew a couple of people who also had the new RS, before me. So I contacted them to check if their cars also had these quality issues, and the reply was from "no" to "I do not think so", it is only when I visited those cars that I found out most of the problems were the same.
What I learned from this;"If you do not want to see them, you will not see them" LOL!
I suggest you contact me and I will walk you through all of them!