I'm glad you did
I wish i had.
Shingeki was one of those stories i got that awesome feeling of "Man, it's gonna be so good re-reading / re-watching the series after it ends" like Game of Thrones and One Piece.
But just like Game of Thrones, the ending was really horrible for me and killed that feeling.
I'm hoping One Piece won't fall on the same trap..
The funny part is that Isayama did the hardest part for me, explaining all the mysteries and biggest questions of the series in a satisfying way, but what killed it was the last events / characters actions / motivations.