Really? Cool, I've never been to a concert like that. What were your impressions?
Obviously even if you have a great seat you don't see things as close as in the subsequent video releases (after all, there were close to 27000 people at each concert) but the atmosphere was really great - the concert-goers know all the songs and wave glow sticks in time with the music all through the concert, and I had the time of my life going over there (5 days, 4 nights) and visited the museums near Ueno station plus the Ghibli museum and railway museum at Saitama and Washinomiya Shrine (of Lucky Star fame) and Akihabara. The concerts are very professionally run - staff were friendly, queues were short and orderly, the venue and surrounds handled the crowds easily.
Each of the Animelo Summer Live 2011 concerts were 5 hours long with a 20 minute interval (4pm-9pm). I was expecting to be seated with everyone else but my travel agent managed to secure me a seat with a guide in the "friends of the bands" area and we were able to go backstage after the concerts and meet the artists. I met Minori Chihara after the first concert and Chiaki Ishikawa after the second concert.
Check the Wikipedia page at Animelo Summer Live - Wikipedia, the free encyclopedia (
http://en.wikipedia.org/wiki/Animelo_Summer_Live) for the set lists. Note the secret guests and also that although most of the artists are announced in advance, the collaborations apart from singing the theme song at the end are also surprises.