>>9886361
Desucon changed leadership. They had one year that everyone got angry and complained a lot because it was poorly done, but after that they've improved a bit.
May be worth mentioning that they've announced that this will be the last year that Desucon is held, so if you want to experience Desucon again this is your last chance. I don't know what will happen in the future after this, there's no con that can easily take over so quickly.
One important thing I didn't mention in my >>9886211 long posts is places to sit down.
The clear winner in this among the three big ones is Torucon. They've many chairs and sofas spread around in smaller groups, very comfy.
Desucon has pretty much no chairs, so most people will sit on the floor along the walls. At panels you can sit obviously though, and if you go to the expensive food salesplace you can sit there too, or outside.
Banzaicon has places to sit, but mostly in the cafe, which is also one of the major places people meet and sit down. Other than that, it's a bit limited outside panels, and it is just regular chairs so not as nice as Torucon, but it may be a bit easier to find a free seat than at Torucon.