It’s incredible. The time skip and change in setting was probably the best thing they could have done because trying to follow up from Season 3 Part 2, which is my favourite arc in all of anime, by doing something similar would be very difficult.
One thing season 4 does better than the rest is making the characters much more interesting and elevates Eren from just sort of being there to being a commanding and intimidating figure who we don’t know whether to root for or not. I like Gabbie and Falco as well, and how Eren and Reiner are mirrored in their personalities and actions.
Showing the other side of the war gave the series more depth than before. It’s not just good vs evil or humans vs Titans anymore. The horrors of war are shown very well.
However, while the season has some very good action, such as the Warhammer Titan fight, the action and the animation in the action is a bit of a step down from the previous seasons. This isn’t a problem with the CGI or the change in artstyle, I actually think the CGI is pretty good and the artstyle is really good, rather there was nothing in the animation that wowed me like the earlier seasons.
Overall, the season had everything Attack on Titan has had in the past and some added elements, deepening the series. However, some the action and animation wasn’t as jaw-dropping as the earlier seasons.
I would give Attack on Titan Season 4 a 9/10.