For those looking at an upgrade in the near future, come prepared for a 'slam dunk' program.
You'll get four sims that cover the same material that the initial course covers in eight...so have your flows, callouts, and profiles down pat. There just isn't enough time to redo very many areas.
The check is a full blown FAA type ride. If you are a first time ATP candidate, you will do steep turns and the Emergency Descent in addition to everything else. Emphasis is on PIC decision making and 'command presence'...not just on flying maneuvers from the left seat.
Good luck.