As a huge fan of the manga, I have to say that the anime pissed me off.
I can't believe that they pushed more than 100 chapters in 24 episodes. It was rushed, they cut scenes that could have given side characters like Veronica, Grimoir, Slader,... more depth and importance. Because of that it lacks emotion, the fights aren't as intense as they felt in the manga and as a manga reader I felt like we were missing some of the bigger plot points because it was all rushed and simplified for anime only viewers.
The thing that also annoyed me was the wiping out of LGBT related material:
-when King is explaining to Diane what lovers are, in the manga he talks about two people who love each other while the anime made sure to specify it should only be a man and a woman.
- during a scene Gowther makes the entire guard of Lioness believe that himself, Ban and Meliodas are people they love so they can't harm them. In the manga this included lovers, while in the anime they referred to them as brothers or friends or sons.
- Slader is gay in the manga and the anime made sure to cut out as much scenes of him as they could. There is also a bit of flirting going on between him and Gowther and this is also taken out of it. The anime even cut their fight as a result of this.
The manga is a solid 8,5/10.The anime is a weak 6/10 for me. Really disappointing. This could have been something amazing.