More sessions, and too many at one time, making it hard to choose which ones to attend. Some offer significant added value in the attendance; some don’t (the corresponding paper on the Conference CD suffices).
And some may not be worth going to at all. I ran across an old acquaintance, Paul G., who mentioned that he decided to leave a session devoted to petroleum industry terminology when the speaker described the distillation column as an apparatus in which “long chains of hydrocarbons are broken down into shorter chains” (a function actually performed by various “cracking” units, whereas the distillation column separates crude oil into component fractions, some of which are later cracked).
You can’t win them all.
Next year’s conference is scheduled for about the same time in my back yard, in Denver.