Season 2: Good but with less rewatchable quality
Compared to S1, this next adventure in the Log Horizon files does feel like a big step back and a disappointment. The first episode's structure was to entice people about what's to come, but really it only left a confusing mess. It didn't help that the next 6 or 8 episodes were really slow. S2 had a lot of trouble balancing the two separate plotlines and may have lingered on them longer than necessary.
Another hard pill to swallow when it comes to S2 is that it doesn't begin to be as interesting as S1 until much later. The members of Log Horizon, save for Akatsuki, seem to be missing as the story focuses on a serial killer and incorporates the other guilds. There are some good moments with the younger members of Log Horizon later on when they get their first quest, and the world-building finally catches up to them once Shiroe finds out important information on potentially going home, but for the majority of S2, it felt like it was random stories that didn't flow well into one another, waiting to get to this important piece of information.
I'm giving it a 7 for now, but there's a good chance that S2 will drop to a 6 in the near future upon another rewatch.