It was my first cs go event I've been to so I might be biased. Everything was very nice, there was actually a lot of shit to do during the breaks, you should check out 3kliksphillips video experiences about those, he made a good effort making those. The ENCE vs Liquid game was the most memorable for me, the energy and the chanting from the crowd was insane. But the most memorable for me was the initial impression. My train arrived a bit later than planned and just as it reached Katowice's train station the first game began. I turned on Audio Only stream with twitch and started running towards the arena(it was like 1.5km away from the train station). While I was running I suddenly realized that HenryG's voice isn't coming from the headphones anymore, so I took them off and I could hear his voice, even though I was really far away from the arena. So yeah then I just quickly went in, and got goosebumps upon entering the arena, and seeing that view of the biig screen and the players (Which I have seen only through a screen for the past 4 years).
I wish I was there with my friends though :0