Honestly, the more I've gone to Expo, the more I've disliked it. I think that the guys there have done is great, but the fact that there's no upper limit to the amount of people means that there are often far larger crowds than I enjoy, and this also means that costumes get broken.
The wings I wore as Abel are a good example, I've worn them before and had no issues, wore them to expo, the copper tubing inside them has snapped from all of the people pushing me around.
People are also far ruder I've found, shoving past someone is one thing, but not apologising is far worse in my opinion.
I've been going to Expos since 2005 and have made some fantastic friends from going, but these days I generally have more fun in the hotel than I do inside the actual event.
The cosplay side of things is run well and the people that run it are fantastic, but the rest of it doesn't really appeal to me any more. Once you start going to other conventions where you can watch animé, sing karaoke, play games etc. in proper comfort or where you can sit in the middle of the convention with friends all around you and RELAX...that's what it's all about for me.
And expo...just doesn't have that anymore. You're hard pressed to find somewhere to sit inside the entirety of the ExCel centre these days.
Although I find it hard to say that Expo is "doing it wrong", I would definitely say it's not "doing it right" for cosplayers, because of the nature of the event. I keep wondering why people go (for me it's because it's easy to get to). It doesn't have the stuff a con has, but still gets the cosplayers.
(I also keep wanting to organise a similar event that's catered for cosplayers. But. I don't know if my project management skills will transfer well, and obviously, no funding. Maybe after my cosplay shop gets on track...)