First, this series is rated for R17, for a reason.
# Story
By far one of the best isekai series made. The story is nice and well-paced, there are no boring moments in this series, on every episode, there is more happening than on 90% of other animes and it's clear that it's well thought. There are sometimes things that could be skipped but I think all parts are important for characters, especially to show character growth. World in this series also seems to be well thought, there is quite a lot of different things that have been thought well, and keeps me interested to see more.
# Art
Artstyle fits perfectly for themes in this anime, (also no bs 3D), on some points there was something that could have been better but overall I grade this perfect.
# Sound
The music and sounds are also really well done and nothing feels out of place. Sometimes I thought there was missing something as if too little background noise. The music fits well also to themes and moods in scenes.
# Characters
There is a lot of interesting side characters, some are jerks and some good guys, but almost all of them are anyways more memorable than on much of other anime MCs (especially on the isekai genre), which shows how boring and forced this genre is coming.
# Enjoyment
This series has a lot of controversies that seem to cause unenjoyment for many but I can look past those situations and enjoy the show as a whole. And now watching the second round of this, and even on the second round, I can fully enjoy this series.
# Overall
One of the three best isekai series there is, can't decide the order between this, Overlord or Tensura.