Hey there, I was at the concert too, was standing at the left side of the stage. I'd like to thank you for this account first of all; it'll help me keep those precious memories since I didn't make any kind of recordings (for the same reason as you). Most of your fan-account is spot on.
I was disappointed with our crowd though. The second the girls appeared on stage, hundreds of phones and cameras were raised to either take pictures or record the performance. I understand people do it for memories' sake, but when almost everyone did this, the view of the stage was almost entirely obscured by a wall of human hands. Unless you stood at the very front line, chances are your view would be hindered. Even I had trouble seeing the girls even though I stood just roughly 15 rows away from the stage and I'm fairly tall. Just imagine how difficult it was for people shorter than me and wanted to see the girls in person. It got even worse when the rain began to pour since people also put up umbrellas. At this point, I almost couldn't see the girls at all (that's how I barely got to see them perform Mr Taxi, it was my favourite song too). Good thing the rain stopped really soon and the hands tired down eventually.
Negativity aside, it was a great experience overall. The girls looked really gorgeous in person (too bad Yoona wasn't there), and while I felt there was a little lack of energy from the girls' performances (especially when compared to Shinee), I thought they did reasonably well considering the circumstances (rain, wet stage, strong winds AND dancing in heels).
I didn't know people were talking about their attitude, I thought they kept a cheery image most of the time (except Sunny, she obviously looked upset throughout the performances, more so when the camera focused on her). While there were mistakes through the performance (again, harsh conditions), I really liked the more casual atmosphere. The friend that I dragged along with (he ain't a sone) was also very impressed and felt they did well.
I really felt proud being able to hear Taeyeon sing though, she truly doesn't disappoint (bingo, she's my bias).