I will keep this to one complaint because I want it to be considered:
Five hour+ lines to get badges is simply unacceptable. Sakura Con needs to find a more efficient way to get people through lines. I've been going to conventions of all sorts for years and SC is the only con that ever has an issue with lines being longer than the most popular Disneyland rides.
I realize the length of line is partly because of a small number of registration booths and the fact that people are not just paying for badges, they are being entered into the SC database for ANCEA membership or whatever... but it is really disheartening that year after year SC makes their visitors wait in obscenely long lines. 5 hours. 5 HOURS? I'd guess that the average con attendee may only spend 8-10 hours or less at the convention, which means that 5 hour wait on Friday eats up more than half of many attendees con time.
Many people say "Just pre-reg!" as a way to dismiss this issue, but so long as onsite badges are sold, onsite registration lines should be of a huge concern.
If the staff cannot somehow conceive of a better way to control the massive lines (which is silly, they can absolutely fix this so I don't understand why they haven't yet) then they should at least provide refreshments and games for the people who have to give up HALF OF THEIR DAY to stand in a sweaty, cramped, loud and headache-inducing line.
I would be nicer about this complaint but I first noticed this issue a few years ago, didn't go to SC for a couple of years, and came back to SC 2012 appalled that this issue persists.
I had oodles of fun with everything else but LORD ALMIGHTY THE REGISTRATION PROCESS NEEDS TO BE FIXED!