A few thoughts after being 2v3 days at a conference I walked into with what looks like the wrong set of expectations.
I will not go down the negative route I've been on during the weekend and don't just rant. As it looks lots of people had a way better time there then I did.
But I have a few suggestions to improve things for the next time.
1. Have a few more signs for basic infos (checkin here, fresh cups, used cups, bar upstairs, no-foto-policy...), this is a low hanging fruit and just reduces the barrier a lot and the annoyance for the people at the same time. You had great CI and lots of neat stuff to basically promote yourself, why not take this as an opportunity and extend it? In case of doubt expect that things are not obvious. Also make the no-photo policy more present. Great that you had it but not so great if people don't see it.
2. Seperate floor plans for seperate floor levels, having both in one plan is confusing, esp. for somewhat neurospicy folks.
3. You had an awareness team and a quiet-room, great! (actually the first time in 15+ years of all kinds of conferencing that I needed it...), but having someone from the volunteers open the door every 5min and check if people are ok basically makes this a absurd. Bonus-Points of your quietroom is not at the end of an incredible loud corridor.
4. PLEASE do a shuffled schedule next time, not 4 tracks of the same topic cluster in parallel at the same time. I - and others I know - basically missed the majority of what I/we would love to have attended, simple because it was in parallel all the time.
4. I'm a nerd, Moar powerplugs are <3 ... Ideally at a spot that is not as loud as the tables at the corridor near the seminar rooms had been... You can do diz, I believe in you!
5. make it a bit more clear upfront, that food might not be available for people with allergies :-/...
I wish you all the best for the next time, as said, lot's of people seem to have had a better experience then I did and I think we need more of those events, like what you did there in Germany in the future as well.