The event was amazing. Easily a 9/10 in my book. I am extremely impressed by their production, setup, free stuff, etc... A lot of conventions just feel like a money grab. This one feels like Valve giving back to their Dota Community. The balance of the indoor production, with the open-air huge screens at the outdoor parks is awesome! Key arena is not the greatest. At 6'2" I barely fit in most of the seats, so to be able to get up, go outside, hit a food truck and watch the games outside is great. It is such a cool atmosphere with the water park and the non-dota folks interacting with the nerds.
As for the people, attendees, I have to say well done by you. Nice, friendly, polite, and mostly showered. Asians definitely come out for TI, they probably made up 50% of the crowd. Girl quantity was pretty low, but quality was surprisingly high. The nationalism (USA, USA, USA) chants got kind of cringey for an international event, but I hope most of the foreigners know it is just in good fun.
I saw 3-4 Twitch people I watch semi-regularly. The casters and personalities are all over the place and accessible if you want to say hi. The only one I sought out, was Blitz. I kept it short. I told him he does a great job, big fan, and that he should stream more. I am probably the reason he is quitting casting, lul. The players are a bit harder to interact with, which is understandable. But, they do have meet and greet times setup if you really want an autograph, not my cup of tea.
I have to give a huge recommendation to the Mid-Week tickets. You get the opening ceremony (Gaben), the best of 1's knock out games, the team(s) you care about are still going to be in, small crowds so you can sit anywhere you want, small lines to pick up the swag bag/store purchases, you can partake in the other activities like the VR experience center, and the All-Star match is crazy fun way to finish the week. By Friday and Saturday the arena completely fills up, it is a bit of a pain in the ass, and the teams you care about are probably already on an airplane back home. If I had to choose between the two, Mid-week all the way.