Had both of them in my personal home used cars. People mostly have negative reviews about the 9th gen as compared to the 8th gen but i personally like the 9th gen.
Reasons for what I like the 9th gen:
-An aggressive front end including factory fitted projectors
-Curvy rear end
-More comfort cuz of better seats as compared to the 8th gen
-Interior like a super luxury vehicle including the extra display for the fuel economy, radio, time, etc
-Better fuel economy
-Climate Control
-Less cabin noise due to soft suspension
-Less load on engine due to EPS
Some cons:
-Door cards are made up of low quality material as compared to the 8th gen
-Rear is raised a lot as compared to whole civic generations (but can be lowered in a decent daily driven manner)
Rest people talk about road grip etc whatsoever, give the EuroStar tires a break and get some quality tires i bet you will get a better road grip.
And above all, i love my 7th gen the most 