Well, it seems like their livestream was a complete fail. Most people seemed to get better video by watching a JustinTV stream of the stream rather than the actual one and the audio mix was so messed up that all you could hear was MASSIVE bass going BOOOM, BADUMMM, BOOOOM. It's like a terrible dubstep remix. It's a real shame for the group as a lot of people seemed to tune it, and now have had such a bad first experience.
edit: Just after I wrote this post, seems the sound is fixed
edit2: Post-stream mini review
Seems like the setlist was just K4 + River, Ponytail to Shushu and Heavy Rotation as the encore. All songs were sung in Chinese and quite a few were sung live.
The first few songs were messed up by the terrible audio as mentioned above, but after a while they fixed that issue. Maybe just because it was the morning and I was tired, I didn't really pay attention to the stream much but started to enjoy it more near the end starting from around Melos no Michi. Just before Sasae they had some kind of VTR thing whilst the song was playing and occasionally the girls would start singing as well. It seemed everyone was confused, but then after the VTR they performed the song properly and it was a real highlight of the show, perhaps because quite a few of them were crying after watching the VTR. For the encore, my stream cut out completely for River, but Ponytail and Heavy Rotation sounded really good. These three songs were the standouts for me. I think the one thing that did show up AKB was singing live, and on their very first performance as well. I was hoping for more of a concert rather than a theatre show but I guess this will become their regular stage show now once they have their own theatre.