I only saw this complaint twice, but it's a huge deal that I feel needs to be addressed. Con staff need to know the precise correct times for things and be able to accurately tell others about them. Missing out on a charity bidding hurts not just the con goers, but the charity and the con in general due to a loss of potentially higher bids. If the wrong information is given on accident, it's understandable but something that needs to be corrected. If it's given on purpose, though, it's something that seriously needs to be investigated.
Another small complaint that I know Alabaster already acknowledged, but is serious enough to be brought up again. The security team is there to do their job first and enjoy the con second, and this is especially an issue of the team ends up becoming a hindrance to people trying to enjoy the con themselves. Stories of security members walking slowly in front of crowds and/or leaning against the rails at panels blocking con-goer views is unacceptable behavior from the team. Please make this strongly known to the team for next year's con.
Crowd and Line Control
This is something that I'm bringing up myself, but it's something that easily ruins a good con. If you know that an insanely popular panel will have a huge line, it'd be best to assign a small security team to control the crowd and line from the beginning. I have at least two accounts that I noticed people jumping in line and while the team was good at keeping walkways cleared, they weren't vigilant enough to catch the line-jumpers.
Outside of the panel lines though, there is an issue with people blocking walkways in general. This is especially true for the Market. I couldn't keep count of how many times I had to wait and work around a large group of people who just randomly stopped in the middle of the walkway to talk to each other. It's very disruptive to everyone else.
It seems to me that both of these issues mostly stem from a lack of sufficient security personnel, which if that's the case than the only solution is to strongly encourage more people to volunteer for those positions.