Historicon is awesome; pursuing those things chased in the hunt for the new may not be.
And Mirth hates fun.
I would not describe the Moist in summer as 'fun'. I haven't been to the new venue which I am sure is an improvement, but I am in no hurry to travel back to Lancaster.
It is a large event, but I didn't find it particularly well run. The separation of the sales area into another building from the gaming was a PITA. I did enjoy the lectures offered, mainly because the lecture hall had better AC than the rest of the Moist.
Historicon was better than Origins because I didn't have to drive 13hrs to get there.