It was a great experience for me overall, but let me toss in my 2 cents.
Ren Center - Gorgeous location with amazing architecture and a polite staff of workers. Filled with some very nice places for photos. However, this place is not built for anime cons. It's like 80% hallways. The place does have tons of spacious rooms for panels and the other huge events, but everything around it is a clusterfuck.
The way the volunteer security had to constantly yell at people to keep moving because most of the floors were consumed by lines was a good indicator that something wasn't working out.
Staff - Most everyone I ran into was awesome. Just about everyone I ran into was nice and didn't give me any trouble (possibly because I was armored head to toe..) In fact, the only time I got yelled at was by a random con-goer who seemed to be taking managing the con into her own hands.
I have been hearing unpleasant stories, though. My brother encountered a few aggressive staffers who decided their duty was to police to elevators by literally shoving people around and threatening to take badges. Other stories involved more poor line management with volunteers getting too big for their britches and thinking they had absolute power over attendees.
At one point I encountered a guy who told me he was a volunteer for a panel, but he had no idea what to do. At another point, I had a volunteer approach me and ask to sign off on his hours when I was just standing around minding my business. Seems like some of the volunteers need to be reigned in and probably given some means of identification to make them stick out more.
And.. Events - Everything ran smoothly as far as I could tell. Only a couple events ran long or started late, but I didn't attend that many panels either way.
I definitely want to come back next year, I just want things to be more organized. Hopefully the people running things took notes. This new location must have wreaked havoc for them.