I've watched finally Sword Art Online. I liked it, at least the first half that is. And honestly, if you aren't invested in the romance there's just no point in continuing after the fourteenth episode. Sao's heart is its characters. Everyone feels genuine, they act like real people. There's a moment during the show where a Guild leader learns his whole guild is dead, they were his close friends. He's unable to live with the pain and kills himself. There are also people who aren't able to fight, instead, they just adapt to the circumstances and try to live in this new world. It makes the world believable, I think that's Sword Art Online's strongest aspect. It's not all roses and sunshine though.
In the first half, there are a lot of time jumps and it's jarring. You've just finished an episode and now everything's changed. Its world is also convoluted and some of its characters painfully underutilized. But that's nothing compared to the second half.
The latter half is full of good ideas on paper. Mixing up reality and the virtual world, the relationship between brother and sister, discovering who Leafa is, the politics of different VRMMO etc. Basically, they tried to mix things up a bit. But they really fucked up. I've only ever experienced a good story about an incestuous relationship once. This is not it. It's so fucking weird, especially since you've set up an unbreakable relationship beforehand. I'd like to keep this review short so I won't dig into the numerous problems the second part has. But, you should know it falters heavily in its second act.
Overall I liked SAO, it's charming and has some balls, sometimes. It's not groundbreaking and there are a plethora of better shows out there. But I enjoyed it.