All the places mentioned are good, under non-Expo circumstances.
However, when the Expo comes to town, Markely is THE place to go. They stay open 24hrs a day, have midnight tournaments, and is where all the ACTION players end up. It has been that way for at least 10 years now. So while there are better choices if you want the best tables, or a quiet room, if you want action and things to watch or play in, Markely is the only room to go to during the Expo.
It is a dirty room, with worn cloth, but it is action.
If you want the best equipment, and a clean room, go to Main Line Billiards (Formerly Rack M Up Billiards), in Frazer PA. That is 15 min from the Expo in the opposite direction as Markely.
I've played in all these rooms for 15 years, as I'm from the area.