I never finished it. It had poor characters, as well. Especially the main character. On top of that the dual wielding being a character's great ability was really a throw off. I would think a great fantasy game world like that would've allowed people to dual wield pretty easily.
Even a main character change could've been a choice to help the show around. I'd rather have watched the show from the perspective of the side character who was around in the first episode, instead of the main lead.
And the sadistic characters weren't shocking or interesting at all, which really throws off sadistic characters. They were just kinda there to be the evil group that kills people. But without background or depth, they didn't really seem important, either.
Even having a character who goes through a huge psychological struggle, joins this group, then faces himself and decides to either change people in the group or run from them to get out of the game, or something could've made a better story.
But it boils down to the topic we're in. Great concept, especially for it's time. Extremely poor story telling elements, all the way past the writing, and right down to the characters. The base concept was the only good thing about SAO. But if a story doesn't work, it doesn't work. The author should be bale and willing to identify and change many things, if the need arises to make the story work naturally and still be captivating. This wasn't SAO at all for me. The writer missed the mark of a good story.
But, hey, it is wildly successful. So maybe I'm doing something wrong myself, or I just don't know these things. If you're trying to hit that specific niche of the community, maybe you can disregard all advice here and do the exact opposite, complete with unreasonable murder, and ecchi to pull those pesky plotholes together.